I learned through embarrassment that Mongolian Spots can often appear as bruising. They can be deep brown, slate gray, blue/black in color and are usually found on the lower back or buttocks, but can be found elsewhere. They vary in size from a pinhead to six inches or more across. The child may have one or more of these spots. These spots appear at birth; most fade by two, but some remain longer. Mongolian Spots are common on children of Asian descent, but are also found on those of East African, Native American,Polynesian, Micronesian, and Hispanic descent.
Here is a link that shows a picture: http://en.wikipedia.org/wiki/Mongolian_spot
