[XAML]

<!--Define a control template for a HeaderedItemsControl-->

<Style TargetType="HeaderedItemsControl">

<Setter Property="Template">

<Setter.Value>

<ControlTemplate TargetType="{x:Type HeaderedItemsControl}">

<StackPanel>

<Grid>

<Rectangle Fill="{TemplateBinding Background}"/>

<ContentPresenter ContentSource="Header"/>

</Grid>

<Grid>

<Rectangle Stroke="{TemplateBinding BorderBrush}"/>

<ItemsPresenter Margin="2,0,0,0"/>

</Grid>

</StackPanel>

</ControlTemplate>

</Setter.Value>

</Setter>

</Style>

...

<HeaderedItemsControl xmlns:sys="clr-namespace:System;assembly=mscorlib"

Header="My colors"

Background="SteelBlue"

BorderBrush="DarkSlateBlue">

<sys:String>Red</sys:String>

<sys:String>Yellow</sys:String>

<sys:String>Blue</sys:String>

<sys:String>Green</sys:String>

</HeaderedItemsControl>