Most of us have never thought why the color of our genitals is darker than the rest of the skin. Medical science has put forward various causes for dark genital. The scientific research has proved that genitals and areolas get darker during puberty in male human beings. Several hormonal changes take place in our bodies during puberty. Our bodies produce more sexual hormones the adrenal and the androgen. The excessive production of these hormones causes skin pigmentation. The androgens affect melanocytes and causes dark and pigmented penis.