   Graphics card may not be functioning
  Okay recently my graphics card has been acting up. When I start up the FPS engine from the book OpenGL Game Programming my desktop pixelates and the colors become dark. At first I though it was just the engine, but this also happens when I run unreal tournament 2004, and I get a pop-up "Low Color Depth Test" when I start up Quake 3. Can someone please tell me what could possibly be wrong.   
  If I understand you correctly, then whenever you run the FPS engine or UT2004, then after you exit out of it, you desktop (and the rest of the windows/icons/menus) are messed up color wise. I suppose you've already checked the color quality settings in the display section of your control panel? (Assuming, that is, that you are running Windows). I would first try reinstalling your graphics drivers, and if that doesn't fix it, you could always reformat.   ;  Or, if you're in Windows (don't know about a Linux/Mac equivilant), you could "rollback" before reformating, that's always easier.I'd check the color depth you've got it set on right now. Chances are, you want 32 bit, not 16 bit and definately not 8 bit. Most OSes have the accessible near your monitor resolution.BTW, do you have the latest drivers?   