Messed up colors in Quake III Arena

[Coopersville]

Everything I look at has some sort of rainbow gloss over it, but other than that my game runs fine.

When I run it, I used to get this message:
http://www.geocities.com/tz_coopersville/wtf.GIF

Any ideas on how to fix this?

I'm running on a

P2 400mhz
Windows XP pro
8mb video card
and the rest doesn't really matter in this situation, I think.

[Oblivi0.on]

yes. go into your display properties and change the desktop color depth off of 24bit. use any other setting. but not 24bit.