Changing Validation Color in Telerik UI for WPF Controls

Updated on Mar 18, 2026

Environment

Product Version	2020.3.1020
Product	Telerik UI for WPF

Description

How to change the validation color used in text input controls (like RadWatermarkTextBox, etc.) from the default red to another color.

Solution

To do this, set the ValidationColor property of the corresponding palette.

This can be done in C#:

C#

Windows8Palette.Palette.ValidationColor = Colors.Yellow;

Or alternatively, in XAML:

XAML

<Application.Resources>
    <SolidColorBrush x:Key="{x:Static telerik:Windows8ResourceKey.ValidationBrush}" Color="Purple" />
</Application.Resources>

This approach is applicable in newer themes, starting from Windows8.