Yes - melanin first off is the primary coloring and patterning agent in vertebrates. You look at the stripes of a zebra, for example, that have the effect of misleading the eyes of predators - those stripes are made by concentrations of melanin.

In humans, melanin also is used in the synthesis of vitamin D under exposure to modest levels of ultraviolet. This is why northerly peoples are actually lighter than tropical peoples: lower concentrations of melanin mean that you can harvest vitamin D from the more limited sunlight at higher latitudes.