Octopi, squids, and cuttlefishes, collectively known as cephalopods, are intelligent invertebrates that have the ability to change the color of their skin. One reason they change color is to camouflage themselves from predators and prey.
But, they also use changes in color to communicate. Communication is critical for animals because it can help them reproduce or survive. These particular cephalopods use color signals to exchange information about mating, aggression, or danger.