TreeView - Change TreeViewItem background color without changing expander's color

[vaxolax]

Hi,

I'm building an application which has a TreeView. When a TreeViewItem is selected, it is highlighted by its background switching to red and its foreground switching to white, for aesthetic reasons.

The problem is that when I change the foreground to white, it also changes the expander's color, therefore it switches to white and as my background is white as well, we can't see it anymore.

Is there any way to prevent the expander from changing color, or any way of extending the background all the way to the expander ?