Why Do Some Blond Kids Go Dark?

  

Some children start life as platinum blonds — often called "towheads" — but experience a darkening of hair color before they reach puberty. Just what causes this change in hue?

To begin: Your hair color is determined by the amount of natural pigment, called melanin, you have in your hair. Two distinct types of melanin exist — eumelanin and pheomelanin — and the ratio of these pigments guides hair color.

Eumelanin can be further broken up into two flavors: black and brown. Essentially, the more eumelanin you have in your hair, the darker it will be.

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