Please explain what does it mean when the vagina has a dark color?

Vulvar pigmentation: The outer labia will often appear to be darker than the rest of the body as it accumulates pigment in this location especially if you are a darker pigmented ethnicity. The vulva will also darken in cases where there is a Bartholin gland cyst/infection, hematoma(blood) with injury to the labia, and darkened vulvar hair on the labia.