Red Sea Coral Colors C An iron and complementary trace element complex that promotes the Green colors in corals Coral Colors C Supplement is part of the complete range of complementary major, minor and trace element complexes which together provide the needs for coral growth. A complex of eight "light" metals that includes iron, manganese, cobalt, copper, aluminum, zinc, chrome and nickel. These micro-elements are essential for many bio-chemical metabolic processes, including respiration, production of energy, chlorophyll and photosynthetic catalysts. C elements are related to the green/yellow chromo-proteins. For best results in displaying coral colors use in conjunction with Red Sea's NO3: PO4- X.