I have been trying off and on for some time to fix the alt-tab "layout
based switcher" in compact view to show color on the icons listed. At
some point (kde 4.8?) they became all gray making it hard to tell one
from the other. I could find no configuation option that affected this.
Then I found this article with a simple 2 line patch to 2 files that
fixes the problem. It is here:
In case the link goes away, the patch is attached.
Just edit the two files in /usr/share/kde4 (as root), log out and back
in to kde and you have the nice color icons again when you do alt-tab in
compact or informative mode.
I am running f16 with kde 4.8.5.