I found this multicolor-LED light project on slashdot last week. I think I'm going to have to build one. When I was a kid I had a fascination with electronics, fueled in part by Radio Shack 100-in-1 electronic project kits.
The basic idea of this project is to wire Red, Green, and Blue leds on separate circuits. By adjusting the level of current going to each color, you can make any color. This is the same way a color TV works; by mixing Red, Green, and Blue light.
Jocelyn and I recently bought a small Nissan pickup with a canopy for our planned road trip
across the US next year. We're going to put a foam bed in the back of the truck so we can sleep easily wherever we are. I'm thinking it would be cool to have a similiar LED lighting system set up in the back.