Which hair color is the rarest in humans?

The rarest natural hair color in humans is red hair. It occurs in a small minority of people worldwide, with especially high concentrations in parts of northwestern Europe, including Scotland and Ireland.

Red hair is associated mainly with variants of the MC1R gene on chromosome 16. These variants affect how pigment-producing cells make melanin, leading to relatively high levels of reddish pheomelanin and lower levels of dark eumelanin. The trait is often recessive, so two parents without red hair can still have a red-haired child if both carry relevant variants.

Red hair is not one uniform shade. It can range from strawberry blond and copper to auburn, orange-red, and deep burgundy. Another common misconception is that red hair is found only in people of Celtic ancestry; it also occurs, less frequently, among people from many other populations and regions.

Estimates vary because researchers define hair shades and populations differently, but the central comparison remains stable: black and brown hair are much more common globally, while natural red hair is the least common of the major human hair colors. Red hair also does not inevitably disappear; its associated genetic variants can remain hidden in carriers for generations.