Styling RadDocumentPane tab border and border content individually

[Marcel]

Hello,

I want to style my tabs in the docking control individually, I managed to style the header of the tab.

But the color of the border of the header and the border where the content is shown should also be in the same color.

I followed the approach on this link http://docs.telerik.com/devtools/wpf/controls/raddocking/styles-and-templates/styling-the-radpane

and changed the control template, in the design view of Blend I can see that the color changes for the border of the tab to the color I want but when I run the project it doenst work.

Below is the datatemplate and controltemplate that I created, the datatemplate is working fine but the controltemplate not. The color should be bound to a property of the viewmodel. For the color of the content I see that I can change that in the RadPaneGroup style but I want to do this individually, it should have the same color as the tab. How can I do this, all examples that I see will change the border to 1 color which is used for all the panes?

In the attached image the current and desired state is shown, the red should be the color green in this case for the Order tab, depending which tab is selected the border should change color.

<DataTemplate x:Key="PaneHeaderDataTemplate">
    <DataTemplate.Resources>
        <Style x:Key="PaneHeaderCloseButtonStyle" TargetType="{x:Type telerikControls:RadButton}">
            <Style.Resources>
                <telerikControls:Office_BlackTheme x:Key="Theme"/>

                <SolidColorBrush x:Key="ButtonIconBrush_Normal" Color="#FF696969"/>
                <SolidColorBrush x:Key="ButtonIconBrush_MouseOver" Color="#FF000000"/>
                <SolidColorBrush x:Key="ButtonIconBrush_Pressed" Color="#FF000000"/>
                <SolidColorBrush x:Key="ButtonIconBrush_Disabled" Color="#FF8D8D8D"/>

                <Style x:Key="CloseIconStyle" TargetType="{x:Type Path}">
                    <Setter Property="Data" Value="M0,0 L2,0 2,1 3,1 3,2 5,2 5,1 6,1 6,0 8,0 8,1 7,1 7,2 6,2 6,3 5,3 5,4 6,4 6,5 6,5 7,5 7,6 8,6 8,7 6,7 6,6 5,6 5,5 3,5 3,6 2,6 2,7 0,7 0,6 1,6 1,5 2,5 2,4 3,4 3,3 2,3 2,2 1,2 1,1 0,1 Z"/>
                    <Setter Property="Stretch" Value="Fill"/>
                    <Setter Property="VerticalAlignment" Value="Center"/>
                    <Setter Property="HorizontalAlignment" Value="Center"/>
                </Style>
            </Style.Resources>

            <Setter Property="ToolTip" Value="Close"/>
            <Setter Property="Width" Value="15"/>
            <Setter Property="Height" Value="15"/>
            <Setter Property="IsTabStop" Value="False" />
            <Setter Property="SnapsToDevicePixels" Value="True"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type telerikControls:RadButton}">
                        <Grid x:Name="LayoutRoot">
                            <telerikChromes:ButtonChrome telerikControls:StyleManager.Theme="{StaticResource Theme}" RenderNormal="False" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}"/>
                            <Path x:Name="Icon" Fill="{StaticResource ButtonIconBrush_Normal}" Margin="4,4,4,4" Style="{StaticResource CloseIconStyle}"/>
                        </Grid>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsMouseOver" Value="True">
                                <Setter TargetName="Icon" Property="Fill" Value="{StaticResource ButtonIconBrush_MouseOver}"/>
                            </Trigger>
                            <Trigger Property="IsPressed" Value="True">
                                <Setter TargetName="Icon" Property="Fill" Value="{StaticResource ButtonIconBrush_Pressed}"/>
                            </Trigger>
                            <Trigger Property="IsEnabled" Value="False">
                                <Setter TargetName="Icon" Property="Fill" Value="{StaticResource ButtonIconBrush_Disabled}"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </DataTemplate.Resources>

    <Grid x:Name="headerGrid" Background="{Binding Path=DataContext.WorkspaceSettings.WorkspaceColorName, ElementName=parent}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="Auto"/>
        </Grid.ColumnDefinitions>
        <TextBlock Text="{Binding}"
                                    VerticalAlignment="Center"
                                    TextTrimming="CharacterEllipsis"
                                    TextWrapping="NoWrap"
                                    Height="{Binding ActualHeight, ElementName=CloseButton, Mode=OneWay}"/>
        <telerikControls:RadButton x:Name="CloseButton"
                                        Style="{StaticResource PaneHeaderCloseButtonStyle}"
                                        Command="telerikDocking:RadDockingCommands.Close"
                                        CommandParameter="{Binding Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type telerikDocking:RadDocumentPane}}}"
                                        Visibility="Hidden"
                                        Margin="5,0,0,0"
                                        Grid.Column="1"/>
    </Grid>
    <DataTemplate.Triggers>
        <DataTrigger Binding="{Binding CanUserClose, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type telerikDocking:RadDocumentPane}}}" Value="false">
            <Setter Property="Visibility" Value="Collapsed" TargetName="CloseButton"/>
        </DataTrigger>
        <MultiDataTrigger>
            <MultiDataTrigger.Conditions>
                <Condition Binding="{Binding CanUserClose, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type telerikDocking:RadDocumentPane}}}" Value="true"/>
                <Condition Binding="{Binding IsSelected, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type telerikDocking:RadDocumentPane}}}" Value="true"/>
            </MultiDataTrigger.Conditions>
            <Setter Property="Visibility" Value="Visible" TargetName="CloseButton"/>
        </MultiDataTrigger>
        <MultiDataTrigger>
            <MultiDataTrigger.Conditions>
                <Condition Binding="{Binding CanUserClose, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type telerikDocking:RadDocumentPane}}}" Value="true"/>
                <Condition Binding="{Binding IsMouseOver, Mode=OneWay, RelativeSource={RelativeSource Self}}" Value="true"/>
            </MultiDataTrigger.Conditions>
            <Setter Property="Visibility" Value="Visible" TargetName="CloseButton"/>
        </MultiDataTrigger>
    </DataTemplate.Triggers>
</DataTemplate>

<ControlTemplate x:Key="RadPaneControlTemplate" TargetType="{x:Type telerikDocking:RadDocumentPane}">
    <Grid x:Name="wrapper">
        <VisualStateManager.VisualStateGroups>
            <VisualStateGroup x:Name="CommonStates">
                <VisualState x:Name="Disabled">
                    <Storyboard>
                        <DoubleAnimation BeginTime="0" To="0.33" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="HeaderElement"/>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Normal"/>
                <VisualState x:Name="MouseOver"/>
                <VisualState x:Name="Selected">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="ChromePinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="PinnedStates">
                <VisualState x:Name="Unpinned">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ChromeUnpinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Pinned">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ChromePinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Visibility>Visible</Visibility>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
            <VisualStateGroup x:Name="PlacementStates">
                <VisualState x:Name="HorizontalLeft"/>
                <VisualState x:Name="HorizontalRight"/>
                <VisualState x:Name="HorizontalTop">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="wrapper">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0,0,-1,4</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="HeaderElement">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>6,3</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="HorizontalBottom">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="wrapper">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0,4,-1,0</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="HeaderElement">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>6,3</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="VerticalLeft">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="wrapper">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>0,0,4,-1</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="HeaderElement">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>3,6</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Orientation" Storyboard.TargetName="ChromeUnpinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Orientation>Vertical</Orientation>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Orientation" Storyboard.TargetName="ChromePinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Orientation>Vertical</Orientation>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="VerticalRight">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="wrapper">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>4,0,0,-1</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="HeaderElement">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Thickness>3,6</Thickness>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Orientation" Storyboard.TargetName="ChromeUnpinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Orientation>Vertical</Orientation>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Orientation" Storyboard.TargetName="ChromePinned">
                            <DiscreteObjectKeyFrame KeyTime="0">
                                <DiscreteObjectKeyFrame.Value>
                                    <Orientation>Vertical</Orientation>
                                </DiscreteObjectKeyFrame.Value>
                            </DiscreteObjectKeyFrame>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="VerticalTop"/>
                <VisualState x:Name="VerticalBottom"/>
            </VisualStateGroup>
        </VisualStateManager.VisualStateGroups>
        <telerikChromes:ButtonChrome x:Name="ChromeUnpinned" BorderThickness="1" CornerRadius="2" RenderSelected="{TemplateBinding IsSelected}" RenderHighlighted="{TemplateBinding IsMouseOver}" Visibility="Collapsed">
            <telerikChromes:ButtonChrome.Style>
                <Style TargetType="{x:Type telerikChromes:ButtonChrome}">
                    <Setter Property="Background" Value="{Binding Path=DataContext.WorkspaceSettings.WorkspaceColorName, ElementName=parent}"/>
                    <Setter Property="BorderBrush" Value="{Binding Path=DataContext.WorkspaceSettings.WorkspaceColorName, ElementName=parent}"/>
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type telerikChromes:ButtonChrome}">
                                <Border x:Name="OuterBorder" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="{TemplateBinding CornerRadius}">
                                    <VisualStateManager.VisualStateGroups>
                                        <VisualStateGroup x:Name="CommonStates">
                                            <VisualState x:Name="Disabled">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFE0E0E0"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF989898"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFE0E0E0"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="Normal"/>
                                            <VisualState x:Name="Highlighted">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="#FFFFFBA3" Offset="1"/>
                                                                    <GradientStop Color="#FFFFFBDA"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="Selected">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedHighlighted">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFFFC92B"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="NormalVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="#FFF6F6F6" Offset="0"/>
                                                                    <GradientStop Color="#FFD2D2D2" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="HighlightedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="#FFFFFBA3" Offset="1"/>
                                                                    <GradientStop Color="#FFFFFBDA"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedHighlightedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFFFC92B"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                        </VisualStateGroup>
                                    </VisualStateManager.VisualStateGroups>
                                    <Border x:Name="InnerBorder" BorderBrush="{Binding Path=DataContext.WorkspaceSettings.WorkspaceColorName, ElementName=parent}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding InnerCornerRadius}"/>
                                </Border>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </telerikChromes:ButtonChrome.Style>
        </telerikChromes:ButtonChrome>
        <telerikChromes:ButtonChrome x:Name="ChromePinned" BorderThickness="1,0,1,1" CornerRadius="0,0,2,2" Margin="0,1,0,0" RenderSelected="{TemplateBinding IsSelected}" RenderHighlighted="{TemplateBinding IsMouseOver}" Visibility="Collapsed">
            <telerikChromes:ButtonChrome.Style>
                <Style TargetType="{x:Type telerikChromes:ButtonChrome}">
                    <Setter Property="Background">
                        <Setter.Value>
                            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                <GradientStop Color="#FFF6F6F6" Offset="0"/>
                                <GradientStop Color="#FFD2D2D2" Offset="1"/>
                            </LinearGradientBrush>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="BorderBrush" Value="#FF848484"/>
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type telerikChromes:ButtonChrome}">
                                <Border x:Name="OuterBorder" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="{TemplateBinding CornerRadius}">
                                    <VisualStateManager.VisualStateGroups>
                                        <VisualStateGroup x:Name="CommonStates">
                                            <VisualState x:Name="Disabled">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFE0E0E0"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF989898"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFE0E0E0"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="Normal"/>
                                            <VisualState x:Name="Highlighted">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="#FFFFFBA3" Offset="1"/>
                                                                    <GradientStop Color="#FFFFFBDA"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="Selected">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedHighlighted">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFFFC92B"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="NormalVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="#FFF6F6F6" Offset="0"/>
                                                                    <GradientStop Color="#FFD2D2D2" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="HighlightedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="#FFFFFBA3" Offset="1"/>
                                                                    <GradientStop Color="#FFFFFBDA"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FF848484"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                            <VisualState x:Name="SelectedHighlightedVertical">
                                                <Storyboard>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="InnerBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="White"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <SolidColorBrush Color="#FFFFC92B"/>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="OuterBorder">
                                                        <DiscreteObjectKeyFrame KeyTime="0">
                                                            <DiscreteObjectKeyFrame.Value>
                                                                <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                                                                    <GradientStop Color="White"/>
                                                                    <GradientStop Color="#FFFAFAFA" Offset="1"/>
                                                                </LinearGradientBrush>
                                                            </DiscreteObjectKeyFrame.Value>
                                                        </DiscreteObjectKeyFrame>
                                                    </ObjectAnimationUsingKeyFrames>
                                                </Storyboard>
                                            </VisualState>
                                        </VisualStateGroup>
                                    </VisualStateManager.VisualStateGroups>
                                    <Border x:Name="InnerBorder" BorderBrush="White" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding InnerCornerRadius}"/>
                                </Border>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </telerikChromes:ButtonChrome.Style>
        </telerikChromes:ButtonChrome>
        <Primitives:TabItemContentPresenter x:Name="HeaderElement" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
    </Grid>
</ControlTemplate>


<Style x:Key="PaneStyle" TargetType="{x:Type telerik:RadDocumentPane}">
    <Setter Property="HeaderTemplate" Value="{StaticResource PaneHeaderDataTemplate}"/>
    <Setter Property="ContextMenuTemplate" Value="{x:Null}"/>
    <Setter Property="Template" Value="{StaticResource RadPaneControlTemplate}"/>
</Style>

 

Any help would be appreciated.

Regards,

 

Marcel

[Martin]

Hi Marcel,

Right now, as I see in the style, the Backgrounds are set to a concrete value. What you might need to do is modify the Background of the ButtonChrome (ChromePinned) to point at {Binding RelativeSource={RelativeSource AncestorType=telerikControls:RadDocumentPane}, Path=Background}. 
You might need to modify or remove the animations that change the OuterBorder's Background in the Selected, Hightlighted and MouseOverHighlighted states' Background setters, in order to have all the states in the same colored Background or variations of it. Then you can set Backgrounds of the to the different RadDocumentPanes to the values you desire.

Finally you could use this or a similar approach to changing the background of the selected pane. Give a Name to the RadPaneGroup that holds your RadDocumentPanes and update its Background on LayoutUpdated of the RadSplitContainer that holds it:

<telerik:RadSplitContainer LayoutUpdated="RadSplitContainer_LayoutUpdated">
  <telerik:RadPaneGroup x:Name="PaneGroup1">
    <telerik:RadDocumentPane Header="DocumentPane 1" Background="Red" />
    <telerik:RadDocumentPane Header="DocumentPane 2" Background="Green" />
  </telerik:RadPaneGroup>
</telerik:RadSplitContainer>

private void RadSplitContainer_LayoutUpdated(object sender, EventArgs e)
{
  var selected = PaneGroup1.SelectedItem;
  if (selected != null)
  {
    RadDocumentPane s = selected as RadDocumentPane;
    PaneGroup1.Background = s.Background;
  }
}

Regards,
Martin
Telerik by Progress