Active camouflage the surface, so when marine animals are seen from below, they appear darker than the background. Some species of cephalopod, such as the eye-flash squid and the firefly squid, produce light in photophores on their undersides to match the background. Bioluminescence is common among marine animals, so counterillumination may be widespread, though light has other functions, including attracting prey and signalling. Color change permits camouflage against different backgrounds. Many cephalopods including octopuses, cuttlefish, and squids, and some terrestrial amphibians and reptiles including chameleons and anoles can rapidly change color and pattern, though the major reasons for this include signalling, not
Military camouflage dropped altogether. Late in the Second World War, the USAAF abandoned camouflage paint for some aircraft to lure enemy fighters to attack, while in the Cold War, some aircraft similarly flew with polished metal skins, to reduce drag and weight, or to reduce vulnerability to radiation from nuclear weapons. No single camouflage pattern is effective in all terrains. The effectiveness of a pattern depends on contrast as well as colour tones. Strong contrasts which disrupt outlines are better suited for environments such as forests where the play of light and shade is prominent, while low contrasts are better suited to