This chapter provides an understanding of colorant chemistry-an essential prerequisite to managing the color and color stability of foods. It discusses a process that improves the green color of canned vegetables based on the formation of zinc metallocomplexes was introduced into the United States in 1990. The chapter also provides major regulatory issues that govern the use of food colorants in the United States and around the world. Sodium copper chlorophyllin is a green to black powder prepared from chlorophyll by saponification and replacement of magnesium by copper. Naturally occurring pigments in plants and animal tissues are those that are synthesized and accumulated, or excreted from living cells. Irradiation of meats can cause color changes because of the susceptibility of the myoglobin molecule, especially the iron, to alterations in the chemical environment and to energy input. An important means of stabilizing meat color is to store under appropriate environmental conditions.