Fishes display a wide variety of colors that serve important functions. Their coloration is generally related to their environment and provides camouflage, either through general color resemblance to their backgrounds, variable color change abilities, disruptive patterns, or countershading with dark tops and light undersides. Coloration also functions in communication, both between members of the same species through signals like threats or warnings, and between different species through intimidating color displays to deter predators. Fishes have specialized pigment cells called chromatophores that contain pigments like carotenoids, melanins, and purines to produce their colors, and these cells allow for both rapid and more permanent changes in coloration controlled by hormonal and nervous systems.