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 remained simple two-colour schemes (different upper and under sides) or even dispensed with camouflage altogether. Italian and some Japanese aircraft wore sprayed-on spotted patterns. German aircraft mostly used an angular splint-pattern camouflage, but Germany experimented with different schemes, particularly in the later stages of the war. They also experimented with various spray-on camouflage patterns for tanks and other vehicles, while Allied vehicles remained largely uni-coloured. As they had volunteered in the first World War, women sewed camouflage netting, organizing formalized groups for the work in Australia, Britain, New Zealand and the United States who took part as camoufleurs during the