The reason why the skin color of the vulva is darker than the rest of the body is that after puberty the ovaries begin to secrete estrogen and progesterone periodically, which not only causes the endometrium to change periodically and shed bleeding, but also causes the skin of the vulva to appear colored, so it will appear as a darker skin color of the vulva. Before puberty, the skin color of the vulva is the same as the skin color of the rest of the body. As women enter menopause, the hormone levels in the body begin to decline, especially the estrogen level, which will cause the vulvar skin color to decrease compared to the color at the reproductive age, and the color will appear to diminish compared to that time, mainly due to the action of estrogen.