The setup is 3 TVs facing the wall attached to 3 Atari 2600 consoles, and the Ataris are programmed to play a repeating sequence of color that lasts about 4 minutes. I used Ataris because they're cheap, small, and allow precise control over the video signal.
Each color is made up of two colors that are mixed by displaying one color at the top half of the screen and the other one at the bottom, and the two are swapped at 30Hz. It gives the sense that the colors are flowing. And the refresh frequency for each TV is gently modulated out of sync with the others, which gives the light even more motion.