Pigment is a fancy word for color. It's like a spot on your skin. The types of pigmented birthmarks are:. If you are born with a mole, it is considered a birthmark. People often call these birthmarks "beauty marks. Moles usually are small, round brown spots no bigger than about the size of a pencil eraser , but they sometimes can be larger and can be different colors. They can be pink, skin-colored or black.