Changing SystemColors.ControlBrushKey
did not work for me, I had to change
SystemColors.InactiveSelectionHighlightBrushKey
So instead of:
<SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Red" />
I had to use:
<SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="Red"/>