Skin colour is a polygenetic inheritance and it is controlled by three genes pairs of alleles. The human skin is determined by the amount of melanin it contains. A combination of melanin producing alleles determines the skin color.
In the above question, the person has a skin color that is midway meaning only half of the alleles produced melanin. The total number of alleles is 6 and half of it is 3. So, only 3 alleles were dominant and the remaining three were recessive.
