Before the 17th century, almost all carrots were purple! It was only after the Dutch growers took mutant strains of the purple carrot, including yellow and white carrots and developed gradually the orange carrot that we know today. Purple carrots had the purple pigment anthocyanin which gave them this distinctive color.
Orange carrots were sweeter and more fleshy providing more food per plant, thus they became quickly very popular.
Photo: carrot museum