"Excess pigmentation" is a term used to describe when there is too much color or darkness in a certain area of the skin, hair, or eyes compared to what is normal or desired.
Full definition
Vitamin C also inhibits the production
of excess pigmentation in our skin, which leads to blotchy pigmentation.
«Sun damage from years of unprotected sun exposure leads to
excess pigmentation showing through the thin skin underneath the eyes,» Begoun says.
While excess pigmentation does not cause medical problems, purple, blue and black discoloration of the tongue can be a sign of health problems in a dog with a normally pink tongue.
The cause of
this excess pigmentation is unknown but can occur in mixed breeds as well as show breeds, which can develop spots.