If you feel the nipple getting darker, you can apply some whitening products containing arbutin or lemon juice to the areola. Nipple blackening may be caused by melanin deposition caused by estrogen level in the body, because after women enter puberty, estrogen in the body will become higher, thus stimulating breasts. Pigmentation will aggravate the nipple color, and it may turn black even if it is not stimulated or rubbed. There is generally no need to turn pink. If necessary, drugs or pigments can be used for bleaching. Nipple blackening is not caused by disease and does not require much treatment. Usually wash with warm water, massage yourself, do proper chest expansion exercise, pay attention to diet and keep a good mood.