Since times immemorial, colors in the living world have always fascinated and amazed humans and left them wonderstruck; the present study has also been inspired by their provocative and conspicuous nature. The structural colors, wherein a variety of optical properties emerge as a result of the physical nature of the surface of the tissue, are, however, excluded from the present review. To give a brief account, two predominant structural colors encountered in the biological systems are Tyndall blue colors and iridescent colors. The former are produced as a result of light scattering by very small particles, examples being the color of human eyes and feathers of many birds. The iridescent colors result from interference with light by thin films or laminations, and examples of such colors are abundant in the animal kingdom, in birds, insects, and fishes. It should be noted that no pigment per se is extractable in either of the structural colors discussed. For a detailed account, the readers may refer to Fox (1). The present review deals with pigments or biochromes, the chemical compounds absorbing specific wavelengths of visible light. A broad spectrum of pigments produced in the biological systems are reviewed in relation to their distribution and occurrence in the living world as well as the types, functions, and applications of the pigments in industry and aquaculture. In the last part, attention is focused on the mechanisms of their biosynthesis.