Pigmentation of Skin
The color of the skin is determined by at least five pigments present at different levels and places of the skin. These pigments are:
It is brown is color and is found in the germinative zone of the epidermis.
It resembles the melanin pigment in structure, however it is present diffusely throughout the epidermis.
It is a yellow to orange pigment found in the stratum corneum and the fat cells of dermis and superficial fascia.
It is actually a blood pigment but it can make the skin appear purple in color.
It is the oxygenated form of hemoglobin and is also found in blood however, it can make the skin look red.
The amounts of first three pigments (Melanin, Melanoid and Carotene) vary with race, age and part of the body. In white races, the color of the skin depends chiefly on the vascularity of the dermis and thickness of the keratin. More vascularity means red color and more thickness means white (pale) color. In the lips, where the keratin is thin, the color is red, while in the palms and soles, the keratin is thick and thus the color is white.