For hair color of horses, see Equine coat color. For hair brown hair color shades, see Hair coloring.
A variety of the human hair colors. From top left, clockwise: 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.