As we saw in the chapter dedicated to vision, few organisms are equipped with visual systems as large and sophisticated as arthropods. Except for cave organisms that are often blind, vision is one of the most developed communication channels. The colors and the patterns they form, including in the spectral domains invisible to the human eye, have evolved under the effect of sexual selection and natural selection, and provide many functions in intra- and interspecific communication. They also participate in the body’s thermodynamic balance. This aspect has been dealt with elsewhere. In this chapter, we will present the various visual communication strategies of arthropods involving colors and patterns (Fig. 7.1).