a regular rhythm
With a good color wheel, you can see what will come out when you mix two colors. Pick the two colors in the color wheel, and the color in between will be the outcome. It only works well when the colors are not too far apart in the color wheel. Opposites in the color wheel will make smudgy, greyish-brownish colors.
In red light, I plant will still grow perfectly fine, if not better. Think of it this way. The chlorophyll in a plant is green. This means that it reflects green light and absorbs all other light. So it would absorb Redlight just as easily, if not better than white light, which contains green. The only color light that will not help a plant is green light.