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 blue right is displayed the color liberty. The first recorded use of "liberty" as a color name in English was in 1918. The source of this color is: ISCC-NBS Dictionary of Color Names (1955)--Color Sample of Liberty (color sample #196) Egyptian blue is a pigment that was used in Ancient Egypt. Ultramarine is a blue pigment in use since medieval times. Displayed at right is the colour neon blue. At right is displayed the color delft blue. At right is displayed the color duck blue. The source of this color is: ISCC-NBS Dictionary of Color Names (1955)--Color Sample of Duck Blue