Human hair color account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blond/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several gene pairs control the light versus dark hair color in a cumulative effect. A person's genotype for a multifactorial trait can interact with the environment to produce varying phenotypes (see quantitative trait locus). Natural hair color can be brown, blond, black, red, or white; all natural hair colors including grey, white and lightest blond, are shades of brown. The Fischer–Saller scale, named after Eugen Fischer and , is
Shades of brown color kobicha (brown-nose) is displayed at right. It is one of the Japanese traditional colors that has been in use since 660 AD in the form of various dyes used in designing kimonos. The name "kobicha" comes from the Japanese for the colour of a type of kelp tea, but the word was often used as a synonym for a form of flattery in a curious parallel with the English usage "brown nosing". Displayed at right is the web color Peru. This color was originally called "Peruvian brown". The first recorded use of "Peruvian brown" as a color name in