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 the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat with a Buff-colour'd lining". Burnt umber is made by heating raw umber, which dehydrates the iron oxides and changes them partially to the more reddish hematite. It is used for both oil and water color paint. The first recorded use of "burnt umber" as a color name in English was in 1650. Displayed at right is the color chestnut. Displayed at right is the color chocolate. Displayed at right is the color