On single chip DLP
projectors some people can see colour seperation on the edges of fast moving objects or high contrast areas. DLP projectors build an image by projecting a series of monochrome images so quickly that the brain is fooled into thinking it is one colour image. Like some people are sensitive to televisions and flourescent lights flickering (flicker fusion threshold), some people are sensitive to the rainbow effect. This problems is greatly reduced by inreasing the speed of the colour wheel and increasing the number of or colour segments, hence "7 segment, 5 speed" colour wheels.