Problems binding Foreground property of GroupBox HeaderTemplate

Question

I defined a DataTemplate for the header of my GroupBoxes:

   <Style x:Key="GroupBoxHeaderStyle" TargetType="{x:Type GroupBox}">
        <Setter Property="Foreground" Value="White"></Setter>
        <Setter Property="HeaderTemplate">
            <Setter.Value>
                <DataTemplate>                       
                    <TextBlock Text="{Binding}" Foreground="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Foreground}"
                               FontSize="18" FontFamily="Global User Interface"/>
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>

However the binding done for the foreground doesn't seem to work. The headers of my groupBoxes are always black. What am I doing wrong?

This is how I'm defining the GroupBox:

<GroupBox Header="Views" Margin="1" Foreground="White"
          Style="{StaticResource GroupBoxHeaderStyle}">
          ...

Answer 1

...
<TextBlock Text="{Binding}" Foreground="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}, Path=Foreground}"
           FontSize="18" FontFamily="Global User Interface"/>
...