For the energy of sunlight to be converted and stored into biological systems, it must first be captured by the pigments present in the organisms. There are three major classes of pigments involved in photosynthesis: (bacterio)chlorophylls, carotenoids, and phycobilins. This chapter discusses their general properties and biosynthesis. Each pigment interacts with light to absorb only a narrow range of the spectrum and reflects only certain wavelengths of light so as to produce their distinctive colors. The photosynthetic organisms broaden their light absorption region and increase their optical cross section by combining these various pigments, which have different maximum absorption peaks. Such a “rainbow” array of pigments permits photosynthetic organisms to capture maximally most of the available light; thus there is the opportunity for competitive advantage in any particular habitat by developing the most effective combination of pigments.