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
Snow camouflage observation positions were hand-painted in disruptive patterns by artists known as camoufleurs, and they sometimes varied their patterns seasonally. Uniforms were largely of a single colour, such as the British khaki; but snow camouflage clothes came into use in some armies by 1917. For example, Austro-Hungarian troops on the Italian front used skis and wore snow camouflage smocks and overtrousers over their uniforms, and improvised white cloths over their uniform caps. Several armies in the Second World War in Northern European countries preferred separate winter uniforms rather than oversuits. The Waffen-SS went a step further, developing reversible uniforms with separate