" There is another important difference as well. Human eyes have three visual pigments, allowing us to see color. Octopuses have only one—which would make these masters of camouflage, commanding a glittering rainbow of colors, technically color-blind. How, then, does the octopus decide what colors to turn? New evidence suggests cephalopods might be able to see with their skin. "

― Sy Montgomery , The Soul of an Octopus: A Surprising Exploration Into the Wonder of Consciousness