Thanks :). I actually already know viksoe's site though. He's using COLOR_HIGHLIGHT and then blending to acheive the effect, which is what I'm already doing, but when I change the Selected Items color, I notice that only the border of the selection rectangle changes for the one in explorer. Maybe it's caching the color and not changing in response to WM_SETTINGCHANGE. I guess I'll have to live with it for the time being but I did go through all the colors in stylebuilder so I'm rather annoyed I couldn't find it. It would have been nice if Microsoft's theming documentation came with pictures of the theme parts and colors though.

Thanks, but unfortunately this doesn't have what I'm looking for. Currently I think that perhaps Microsoft decided not to have an API for this as they consider changing the default audio playback device programmatically as something which could be abused.