Dark coloration is due to abundant melanin pigment. Traces of the red coating pigment are still visible. It is responsible for the distribution of melanin pigment in mammals. Green eyes contain the yellowish pigment lipochrome. The color of saffron comes from crocin, a red variety of carotenoid natural pigment. They also used less expensive green earth pigment, or mixed yellow ochre and blue azurite. "Reflex blue" used to be the name of a common blue pigment in ink manufacturing. A lack in one of the pigment genes causes color exceptions. Vermilion is a dense, opaque pigment with a clear, brilliant hue. Tattoos consist of thousands of particles of tattoo pigment suspended in the skin. It is an accessory pigment to chlorophyll. Neanderthal are known to have used ochre, a clay earth pigment. This results in the destruction of skin pigment cells. Vitiligo is a long-term skin condition characterized by patches of the skin losing their pigment. The removal of all the skin pigment with monobenzone is permanent and vigorous.