Mixed light and "pure" light? We all know from our young days that mixing paints give you different colors, like yellow and blue gets green. What i wondered about is what kind of light will it be? If you shine blue and yellow light on something, you will see green. There is also not much difference from natural green emitted by an LED for example. And the screen you look at makes yellow by mixing red and green. Is it a perception thing or is there some frequency merge occuring? What are the differences? For a photoeffect made by shining mixed green light on proper metal will it be for green frequency or for blue? What will a coloblind person see in the mix?