Human skin color is primarily due to the presence of melanin in the skin. Skin color ranges from almost black to white with a pinkish tinge due to blood vessels underneath. Variation in natural skin color is mainly due to genetics, although the evolutionary causes are not completely certain. According to scientific studies, natural human skin color diversity within populations is highest in Sub-Saharan African populations, with skin reflectance values ranging from 19 to 46 (med. 31) compared with European and East Asian populations which have skin reflectance values of 62 to 69 and 50 to 59 respectively. The term "range" is loosely defined in this case, as African albinos have obviously not been taken into consideration when calculating the "range".
The natural skin color can be darkened as a result of tanning due to exposure to sunlight. The leading theory is that skin color adapts to intense sunlight irradiation to provide partial protection against the ultraviolet fraction which produces damage and thus mutations in the DNA of the skin cells. Other factors that can modify skin color include protection from ambient temperature, infections, skin cancer or frostbite, an alteration in food, and sexual selection.
The social significance of differences in skin color has varied across cultures and over time, as demonstrated with regard to social status and racism.
Read more about Human Skin Color: Melanin and Genes, Evolution of Skin Color, Irregular Pigmentation, Exposure To Sun, Geographic Variation, Social Status and Racism
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“There should be more sincerity and heart in human relations, more silence and simplicity in our interactions. Be rude when you’re angry, laugh when something is funny, and answer when you’re asked.”
—Anton Pavlovich Chekhov (1860–1904)
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“Painting seems to be to the eye what dancing is to the limbs. When that has educated the frame to self-possession, to nimbleness, to grace, the steps of the dancing-master are better forgotten; so painting teaches me the splendor of color and the expression of form, and as I see many pictures and higher genius in the art, I see the boundless opulence of the pencil, the indifferency in which the artist stands free to choose out of the possible forms.”
—Ralph Waldo Emerson (1803–1882)