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 Shades of brown Brown is a composite color which can be produced by combining red, yellow, and black pigments, or by a combination of orange and black—as can be seen in the color box at right. The color brown shown at right has a hue code of 30, signifying that is a shade of orange. In the RGB color model used to create all the colors on computer and television screens, brown is made by combining red and green light at different intensities. Brown color names are often not very precise, and some shades, such as beige, can refer to