<telerikInput:RadNumericInput x:Name="numericInput" 
                                          IsEnabled="{Binding IsEnabled}"
                                          Value="{Binding Value,Mode=TwoWay}"
                                          VerticalOptions="Center" 
                                          HorizontalOptions="FillAndExpand">
                <telerikInput:RadNumericInput.Triggers>
                    <DataTrigger TargetType="telerikInput:RadNumericInput"
                                 Binding="{Binding Validator.IsValid}"
                                 Value="False">
                        <Setter Property="BorderStyle">
                            <telerikInput:BorderStyle BorderColor="{DynamicResource ErrorColor}" />
                        </Setter>
                    </DataTrigger>
                </telerikInput:RadNumericInput.Triggers>
            </telerikInput:RadNumericInput>

<telerikInput:RadNumericInput x:Name="numericInput" 
                              IsEnabled="{Binding IsEnabled}"
                              Value="{Binding Value,Mode=TwoWay}"
                              VerticalOptions="Center" 
                              HorizontalOptions="FillAndExpand">
            </telerikInput:RadNumericInput>

<Style TargetType="{x:Type telerikInput:RadNumericInput}">
        <Setter Property="BackgroundColor" Value="{DynamicResource EntryBackgroundColor}" />
    </Style>

    <Style TargetType="{x:Type telerikNumericInput:NumericInputButton}">
        <Setter Property="BorderRadius" Value="5" />
        <Setter Property="BorderColor" Value="{DynamicResource PrimaryColor}"/>
        <Setter Property="TextColor" Value="{DynamicResource TextThemeColor}"/>
        <Setter Property="BackgroundColor" Value="{DynamicResource EntryBackgroundColor}"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Padding" Value="0,0,0,0"/>
    </Style>
    
    <Style TargetType="{x:Type telerikNumericInput:NumericInputEntry}">
        <Setter Property="TextColor" Value="{DynamicResource TextThemeColor}"/>
        <Setter Property="Padding" Value="0,0,0,0"/>
        <Setter Property="Keyboard" Value="Numeric"/>
        <Setter Property="BorderStyle">
            <Setter.Value>
                <telerikInput:BorderStyle>
                    <telerikInput:BorderStyle.BorderThickness>
                        <OnPlatform x:TypeArguments="Thickness" Default="1">
                            <On Platform="Android" Value="1"/>
                            <On Platform="iOS" Value="1"/>
                            <On Platform="UWP" Value="1"/>
                        </OnPlatform>
                    </telerikInput:BorderStyle.BorderThickness>
                </telerikInput:BorderStyle>
            </Setter.Value>
        </Setter>
    </Style>

private CalendarCellStyle EvaluateCellStyle(CalendarCell cell)
{
    Color background = default(Color);
    Color selectedCellForegroundColor = default(Color);
    Color todayBorderColor = Color.FromRgb(115, 174, 239);
    double dayNamesFontSize = default(double);
    double fontSize = default(double);
    Thickness todayBorderThickness = default(Thickness);

    switch (Device.RuntimePlatform)
    {
        case "iOS":
            background = Color.White;
            selectedCellForegroundColor = Color.White;
            fontSize = 14;
            dayNamesFontSize = 14;
            todayBorderThickness = new Thickness(2);
            break;
        case "Android":
            background = Color.White;
            selectedCellForegroundColor = Color.FromHex("FF0066CC");
            fontSize = 15;
            dayNamesFontSize = 15;
            todayBorderThickness = new Thickness(1);
            break;
        case "UWP":
            background = Color.FromRgb(30, 30, 30);
            selectedCellForegroundColor = Color.White;
            fontSize = 17;
            dayNamesFontSize = 17;
            todayBorderThickness = new Thickness(2);
            break;
    }

    if (cell.Type == CalendarCellType.DayName)
    {
        return new CalendarCellStyle
        {
            BackgroundColor = Color.LightGray,
            FontSize = dayNamesFontSize,
            FontAttributes = FontAttributes.Bold,
            TextColor = Color.FromRgb(0, 122, 255)
        };
    }

    var defaultStyle = new CalendarCellStyle
    {
        BackgroundColor = background,
        FontSize = fontSize,
        FontAttributes = FontAttributes.None,
        TextColor = Color.FromRgb(139, 209, 0)
    };

    if (cell is CalendarDayCell dayCell)
    {
        if (dayCell.IsFromCurrentMonth)
        {
            if (dayCell.IsToday)
            {
                defaultStyle.TextColor = Color.FromRgb(0, 122, 255);
                defaultStyle.FontAttributes = FontAttributes.Bold;
                defaultStyle.BorderColor = todayBorderColor;
                defaultStyle.BorderThickness = todayBorderThickness;
            }
        }
        else
        {
            if (dayCell.IsToday)
            {
                defaultStyle.TextColor = todayBorderColor;
                defaultStyle.BorderColor = todayBorderColor;
                defaultStyle.BorderThickness = todayBorderThickness;
            }
            else
            {
                
                  if (dayCell.Date.DayOfWeek == DayOfWeek.Sunday || dayCell.Date.DayOfWeek == DayOfWeek.Saturday)
                  {
                           defaultStyle.TextColor = Color.Red;
                  }
                  else
                  {
                           defaultStyle.TextColor = Color.Gray;
                  }

            }
        }

        if (dayCell.IsSelected)
        {
            defaultStyle.TextColor = selectedCellForegroundColor;
            defaultStyle.BorderColor = Color.FromHex("FF0066CC");
        }

        return defaultStyle;
    }

    return null; // default style
}