Squid chromatophores in action. This small squid is a specimen taken from a fishing vessel for scientific analysis (I work for a state scientific monitoring agency) and it's so fresh that the color-changing cells are still alive. They're just functioning off of reflex in this clip, but when cephalopods (squid, octopuses and cuttlefish) are alive they can control these cells extremely well and use them for camouflage and visual communication with other members of their species.