Red hair ranges from light strawberry blond shades to titian, copper and less commonly "true" red. It is caused by a variation in the Mc1r gene and is recessive. Red hair has the highest amounts of pheomelanin, around 67%, and usually low levels of eumelanin. At 1-2% of the population, it is the least common hair color in the world. It is most prominently found in Scotland, Ireland and England. Scotland has the highest proportion of redheads; 13 percent of the population has red hair and approximately 40 percent carries the recessive redhead gene.