For hair color of horses, see Equine coat color. For hair colorants, see Hair coloring. A variety of the human hair colors. From top left, all natural hair color: black, brown, blonde, white, red.
Hair color is the pigmentation of hair follicles due to two types of melanin: eumelanin and pheomelanin. This section does not cite any sources. Two types of pigment give hair its color: eumelanin and pheomelanin. Pheomelanin colors hair orange and red. All humans have some pheomelanin in their hair.
Pheomelanin is more bio-chemically stable than black eumelanin, but less bio-chemically stable than brown eumelanin, so it breaks down more slowly when oxidized. This is why bleach gives darker hair a reddish tinge during the artificial coloring process. As the pheomelanin continues to break down, the hair will gradually become red, then orange, then yellow, and finally white. The genetics of hair colors are not yet firmly established. According to one theory, at least two gene pairs control human hair color.
A person with two copies of the red-haired allele will have red hair. Several gene pairs control the light versus dark hair color in a cumulative effect. Black hair is the darkest hair color. It has large amounts of eumelanin and is less dense than other hair colors. Brown hair is characterized by higher levels of eumelanin and lower levels of pheomelanin.
Brown-haired girls or women are often known as brunette. Chestnut hair is a hair color which is a reddish shade of brown hair. In contrast to auburn hair, the reddish shade of chestnut is darker. Chestnut hair is common among the native peoples of Northern, Central, Western, and Eastern Europe.
Strawberry blond, a mixture of blond and red hair, is a much rarer type containing the most pheomelanin. Blond hair can have almost any proportion of pheomelanin and eumelanin, but has only small amounts of both. More pheomelanin creates a more golden or strawberry blond color, and more eumelanin creates an ash or sandy blond color. Many children born with blond hair develop darker hair as they age, with the majority of natural blonds developing a hair color of a dark blond hue by the time they reach middle age. Auburn hair ranges along a spectrum of light to dark red-brown shades. It is most commonly found in individuals of Northern and Western European descent.
Red hair ranges from light strawberry blond shades to titian, copper and less commonly “true” red. It is caused by a variation in the Mc1r gene and is recessive. For the Native American leader, see White Hair. For the fictional character, see Whitehair. Gray or white hair—sometimes colloquially called “salt and pepper” when it is ‘peppered’ throughout dark hair—is not caused by a true gray or white pigment, but is due to a lack of pigmentation and melanin. The clear hairs appear as gray or white because of the way light is reflected from the hairs.