A variety of the gray hair no more pdf free download hair colors. The darker a person’s natural hair color is, the more individual hair follicles they have on their scalp.
Levels of melanin can vary over time causing a person’s hair color to change, and it is possible to have hair follicles of more than one color on the same person. All humans have some pheomelanin in their hair. A low concentration of brown eumelanin results in blond hair, whereas a higher concentration of brown eumelanin results in brown hair. High amounts of black eumelanin result in black hair, while low concentrations result in white hair. 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. This explains why two brown-haired parents can produce a blond-haired child. However, this can only be possible if both parent are heterozygous in hair color- meaning that both of them have one dominant brown hair allele and one recessive allele for blond hair, but as dominant traits mask recessive ones the parents both have brown hair. 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.