Nipples and labia majora turn black with age, because the precipitation of melanin will be intense with age. Commonly known as "women who have had sexual intercourse experience, the color of nipples or labia majora and labia minora will turn black", which is actually wrong. Regarding labia minora, Morii, an associate professor at Shiga University, conducted a survey of 3200 female genitalia. Associate Professor Gersey said that sexual experience has nothing to do with pigmentation. Although there is no investigation on nipples, it seems that the color will not necessarily be black if the number of sexual intercourse is more.

It is genetic factors that determine the primary colors of nipple or labia majora and labia minora. Pigmentation of male genital scrotum is also caused by genetic factors. Pigment precipitation sometimes occurs in the scrotum of newborn boys. Young women who have no experience in pregnancy and childbirth are born with black nipples. It is impolite to think that she has been played. Women's nipples and areola will change color rapidly after menopause, which is caused by hormonal changes.