What is the most rare hair color?

Natural red hair is the rarest hair color in the world, occurring in only 1-2% of the population. Red hair is caused by a mutation in the melanocortin-1 receptor (MC1R) gene, which results in the production of pheomelanin instead of eumelanin. Pheomelanin is a reddish-yellow pigment, while eumelanin is a brown-black pigment.

Red hair is most common in people of Northern European descent, particularly in Scotland, Ireland, and Wales. It is also found in some parts of Asia, Africa, and the Middle East.