Question

but different people have different amount _ each pigment

Answer 1

Human skin color ranges in variety from the darkest brown to the lightest hues. An individual's skin pigmentation is the result of genetics, being the product of both of the individual's biological parents' genetic makeup, and exposure to sun. In evolution, skin pigmentation in human beings evolved by a process of natural selection primarily to regulate the amount of ultraviolet radiationpenetrating the skin, controlling its biochemical effects.[1]

Answer 2

It may be melanin....... Hope it would be correct