I'm using KDE 4.3 RC in conjunction with the Nitrogen window manager theme for KWin and I love it. The only problem, however, is that the title-bar is two-toned and has a fade (radial blending) that makes GTK apps stick out like a sore thumb (as is the case with the oxygen, and ozone themes.) A bummer, but with Nitrogen you can use a "window class" name for apps and change the behavior! Here's where things get tricky:

I don't know the window class name for GTK apps . I tried "GTK.Window" and "GTK" and I'm all out of ideas. Google was no help, but I'm hoping someone here can help me.