The color of a woman’s vulva is darker than that of the surrounding skin, mainly due to the cyclic secretion of estrogen by the ovaries after puberty, which causes the skin and mucous membranes of the vulva to stain, so the color will be darker than that of the surrounding skin, especially after pregnancy when the estrogen increases by thousands of times, and this staining phenomenon will be aggravated. Therefore, during pregnancy, not only the color of the vulva is darker than before, but also the color of the nipples and areola will become darker, mainly due to the effect of estrogen. This phenomenon is a normal physiological phenomenon, so there is no need to be nervous clinically. Before puberty, the ovaries do not undergo cyclic changes and do not secrete estrogen and progesterone, so the color of the vulva in prepubescent women is the same as that of the surrounding skin.