Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color. The Common Germanic adjective *brûnoz, *brûnâ meant both dark colors and a glistening or shining quality, whence burnish. The current meaning developed in Middle English from the 14th century.
The adjective is applied to naturally occurring colors, referring to animal fur, human hair, human skin pigmentation (tans), partially charred or carbonized fiber as in toasted bread and other foods, peat, withered leaves, etc.
In terms of the visible spectrum, "brown" refers to high wavelength (low frequency) hues, yellow, orange, or red, in combination with low luminance or saturation. Since brown may cover a wide range of the visible spectrum, composite adjectives are used such as red brown, yellowish brown, dark brown or light brown.