what is additive and subtractive colors?
Additive and subtractive colors has to do with color perception. Pigments (coloring in objects) reflect the color that you perceive. So for example a red square appears red because it predominantly reflects red light. If you took that pigment and mixed it with a blue pigment you get purple, if you add green pigment to that you would get a dark grey. Pigments are subtractive colors. But with light, if you take red light and blue light and combine them you get magenta light, and its brighter than either individual beam because you have twice the amount of light. If you were to add green light to that, you'd get white light and again it would be a brighter beam. Light is additive.
