Answer
Ok here's the plain English version. Let's say you are looking at a black screen with a white light in the center. The way DLP works with a color wheel, it can't project pure white light on the spot where the light bulb is. It's actually flashing all three primary colors, in turn, to create the white. Looking at it, you won't notice it. However, dart your eyes quickly from left to right as if you were scanning the TV screen and now the light is spread out like a line. When you dart your eye across the screen, the white light is now rainbow colored. You can see the same effect in space, like star fields in sci fi movies. I can see it, not all people can. Just look at any DLP playing at bestbuy, during standard material you will never see it. But in case you are curious, that's the deal, you can test your eyes and see if it bothers you. I don't think 3 chip DLPs are common, and this effect is gone if three color LEDs are used. Samsung made them, but dropped them, not sure why.