Octopus, cuttlefish, squid, and other members of the cephalopod class are masters of color-change and camouflage. Here’s an octopus:
Cephalopods, in almost all cases, are said to be colorblind.
-Peter Godfrey-Smith, in Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness
How do they do it?