In normal state, the color of glans should be pink or dark red, and may change to dark red or purple after erection. If the color of the glans is too dark in the normal state, purple or black, it is abnormal. Under normal circumstances, the color of the glans should be pink. With age and melanin deposition in the body, the color of the glans may deepen and become dark red, which is a normal phenomenon. When the penis is erect and engorged with blood, the color of the glans may change to dark red or purple. If the normal state of the glans is too dark, purple, black, it is abnormal. If the usual excessive masturbation, affecting the blood supply of the penis, it may lead to the dark color of the glans. Secondly, if the glans is not treated for a long time, so that the glans is stimulated by inflammation for a long time, it may also lead to the glans becoming darker in color, purple, black. If the color of the glans is too dark, purple or black under normal condition, it is recommended to go to the hospital in time.