In fact, dogs often have small patches of dark pigment on their skin — you just can't see them through their coats. (dogcare.dailypuppy.com)
Both pure bred and mixed breed dogs can have dark pigment in their mouths. (petsmagazine.com.sg)
Living on bright ice is a tough gig, so certain kinds of algae produce dark pigments to protect themselves from being harmed by too much solar radiation. (ensia.com)