One wish to each

Three blondes were walking through the desert when they found a magic genie's lamp. After rubbing the lamp to make the genie appear, he said, "I will grant three wishes, one for each of you." The first said, "I wish I were smarter". So she became a redhead. The second blonde said "I wish I were smarter than her." She became a brunette. The third blond said "I wish I were smarter than both of them." So she became a man.