This demo shows how color addition works on your TV set (or computer monitor). The Red, Green, and Blue (RGB) colors (known as primary colors) can be 'mixed' to produce any other color. The absence of all three colors gives black, while the proper ratio of all three produces white. After turning on the various spotlights, you can drag the colors around the screen to explore different color mixing.
I'm still working on getting these colors to look correct on different systems...so stay tuned for perfection :)