Is there any way to make kwin force the window shadow to be a particular color? Right now it tries to contrast itself with the background (resulting in a white glow against a darker background), which is inconsistent and ugly.

Is there a setting, hidden or otherwise where I can disable this behavior (I'm open to patching and recompiling if necessary).

I tried to set it in the desktop preferences, but no matter what color I chose, it was ignored. Also, any opacity setting greater than 30% or so would result in a white shadow, regardless of background color.