the color of our skin basically performs two functions: to block UV radiation, and to produce Vitamin D (needed to absorb calcium).
our skin has to absorb a specific spectrum to be able to produce Vitamin D (like how plants have to absorb green) - that color is yellow-brown. however, depending on the amount of the substance (melonin), the color can LOOK any where from white to black.
it isn't green becuase that's not the right color needed...
Thanks wedesdo. I learned something.
Its like the fish in the deep ocean have bright colors that correspond with the light spectrum...deeper it gets the different colors absorb more light. Never really thought about how that applies to humans too though.