Blond (MASC) or blonde (FEM), also referred to as fair hair, is a human hair color characterized by low levels of eumelanin, the dark pigment. The resultant visible hue depends on various factors, but always has some yellowish color. The color can be from the very pale blond (caused by a patchy, scarce distribution of pigment) to reddish "strawberry" blond or golden-brownish ("sandy") blond colors (the latter with more eumelanin). Occasionally, the state of being blond, and specifically the occurrence of blond traits in a predominantly dark or colored population are referred to as blondism.
Because hair color tends to darken with age, natural blond hair is significantly less common in adulthood. Naturally occurring blond hair is primarily found in people living in or descended from people who lived in Northern Europe, and may have evolved alongside the development of light skin that enables more efficient synthesis of vitamin D, due to northern Europe's lower levels of sunlight. Blond hair has also developed in other populations, although it is usually not as common, and can be found among the native populations of the Solomon Islands, Vanuatu, and Fiji; among the Berbers of North Africa; and among some Asian people.