response: Red hair naturally happens in 1 to 2% of the human population although I'm not sure fi it is the least common hair color.
original_response: I would say it is red hair since only 1-2% of the population has it. It's a shame because it is very pretty.
history: I have brown hair, quite common I guess. Yes, it is below black hair for most common hair color. And what is the least common hair color?
knowledge: Red hair (or ginger hair) occurs naturally in 1–2% of the human population.