Infant with birthmarks have a colored area of the skin that is present at birth.

Birthmarks occur when blood vessels group together under the surface of the skin. They may be blue, purple, pink or red. Birthmarks tend to be bright red or purple when the blood vessels are located close to the skin surface, and they tend to be blue or pink when the blood vessels are located further beneath the skin. The surface of a birthmark may be flat or swollen.