The primary light colors are red, blue and green. When these are mixed, you get white light.
How come if I mix red, green, and blue paint, I don’t get a white yard?
Asker: Evelyn, age 20
Answer
If you mix beams of light, you really add up the colors (additive color mixing).
Paint pigments get their color by absorbing a certain color and reflecting the rest, so they subtract a color.
See attached applets.
Answered by
Professor Walter Lauriks
Physics Acoustics
Catholic University of Leuven
Old Market 13 3000 Leuven
https://www.kuleuven.be/
Old Market 13 3000 Leuven
https://www.kuleuven.be/
.