These are skin discolorations that you have at or shortly after birth. Pigmented birthmarks are usually flat and smooth, and range in color from white to tan to blue. They come in several types. They include Mongolian spots -- bruised or bluish in color, typically appearing on the buttocks or lower back; cafe-au-lait spots -- light brown; and typical moles that appear at birth, which are also called congenital nevi. Moles should be monitored for color, shape, or size changes, and/or itching or bleeding.