Rainbow effect, also called RGB flashes, can be viewed as the shadow or flashes of red, green, and blue colors.
This phenomenon often occurs when a bright object appears on an almost dark background, such as in the credits rolling at the end of most movies. For some people, rainbows are always visible, while others rarely see them unless they move their heads quickly along the frame.
“Rainbow effect” is a unique phenomenon of single-chip DLP projector. As the single-chip DLP projectors use a color wheel to control colors, there is really only one color on the screen at any given time. If a person’s eye moves quickly in front of a projection screen, the combination of colors in the composite image will be visible to the naked eye.
Single-chip DLP projectors manufacturers will eliminate this defect by using faster color wheel speeds and more color wheel segments, which is the 2x, 3x, or 4X color wheel on the market, which effectively lowers the rainbow effect occurrence but cannot completely solve the problem. Some DLP projectors manufacturers turn to 3DLP projectors to avoid the rainbow effect, but the cost is much higher.