Ever wonder why your natural hair color is the shade it is? Oddly enough, color is one of the most obvious characteristics of hair, yet— as far as we know— it has no biological function for humans. For instance, hair color does not protect the hair from the harmful effects of sunlight in the same way that hair itself protects the scalp.
Your hair is a certain color due to the presence of a pigment known as melanin. Melanin is formed in special pigment-producing cells called melanocytes in the hair bulb during anagen, the growing phase of each hair. The melanin granules lie along the amino acid chains of the proteins. Under a microscope, this looks very similar to a string of pearls.
Melanin is found in two forms: eumelanin and pheomelanin. Eumelanin is the dark pigment which predominates in black and brunette hair. Pheomelanin is a lighter pigment, found in red and blond hair. The actual combination of pigments in one individual head of hair is determined by the person’s genes. Many people’s hair contains a mixture of both.
The different shades of hair color that people have are due to differences in the overall quantities of melanin in their hair. The more eumelanin there is, the darker the hair. Not only do the mixture and the shade vary from one person to the next, but it also varies across one person’s head.
The range of colors produced by melanin is limited to shades of yellow, brown, red and black. Grey hairs only contain a few melanin granules, spread throughout the hair. White hairs don’t actually contain melanin at all; their whiteness is an optical illusion due to the way they reflect the light.