The major determinant of skin color is the activity of melanocytes, i.e. the quantity and quality of pigment production, not the melanocyte density. Skin pigmentation requires the cooperation between melanocyte-keratinocyte-fibroblast. The melanin pigments are: eumelanins, pheomelanins and trichroms. Regardless of the melanin type synthesized, the starting point of biosynthesis is tyrosine. This involves the activity of tyrosinase and related proteins which possess the catalytic abilities to modify the melanin products.

Melanocytes contain a unique intracytoplasmic organelle – the melanosome, which is the site of melanin biosynthesis, the pigment is produced, then transferred to the keratinocytes, where it is distributed as a supranuclear cap, having an essential role in protecting the DNA against ultraviolet radiation.

Melanosomes intracellular transport is done by motor proteins: myosin V, kynesine and dyneine. UV exposure increases their anterograde transport. There is an inverse correlation between the constitutive color of the skin and the rate of skin cancer, those with light colored skin are 50 times more likely to develop basal or squamous skin carcinoma and 13 times more likely to develop malignant melanoma than those with darker skin.