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 patterns of the new nations changed, coming to resemble the camouflage patterns used by the armies of their neighbours. The authors note that military camouflage resembles animal coloration in having multiple simultaneous functions. Seasons may play a role in some regions. A dramatic change in colour and texture is created by seasonal snowy conditions in northern latitudes, necessitating repainting of vehicles and separate snow oversuits. The Eastern and northern European countries have a tradition for separate winter uniforms rather than oversuits. During the Second World War, the Waffen-SS went a step further, developing reversible uniforms with separate schemes for summer