If irregular dark or light skin spots are undesirable to you, you are not alone. Irregular skin pigmentation can impact all ages, races and skin types. Pigmentation refers to the colouring of the skin. This colouring is created by the deposition of the pigment melanin. Melanocytes are the cells that produce melanin and in some cases they can become damaged, leading to various pigmentation disorders that can affect the skin on the face and body.