Cryptic colouration, is another name for camouflage, a defence strategy that creatures use to disguise their appearance, or to mask their location, their identity, or movement. It both allows prey to avoid predators, and predators to sneak up on prey.
Background matching is probably the most common camouflage tactic. In background matching, a species conceals itself by resembling its surroundings in coloration, pattern, or even movement. Some of the park’s inhabitants are astonishingly good at this.
A tawny owl  and a poplar hawkmoth  demonstrating almost perfect background matching.
Disruptive colouration disguises a species’ identity so that predators can’t tell what they are looking at. Many butterflies have eyespots on the upper part of their wings which resemble the eyes of animals much larger than a butterfly and which may make a predator pause just long enough for the butterfly to escape. A hibernating peacock, its dark underwings beautifully camouflaged to match the background of its hibernation site, flashes brightly coloured eyespots that resemble the eyes of an owl if it is disturbed.
A peacock butterfly uses background matching to hide in hibernation  and disruptive colouration  to persuade a predator that it is dealing with something much larger and more dangerous than a butterfly.
Other examples of disruptive colouration are the creatures that mimic the warning colouration that some organisms use to advertise either that they are armed or that they are unpalatable. Some species of harmless and perfectly edible hoverflies wear the black and yellow warning stripes of an angry wasp or a toxic cinnabar moth caterpillar.
a harmless and edible hoverfly  pretending to be a wasp 
In the summer of 2020 we found wasp spiders in the park. While they look big and scary to the average arachnophobe, they are harmless; they are wearing their black and yellow stripes to persuade a foraging mouse or bird that they might bite or taste bad.
Cinnabar moth caterpillars are toxic  but our wasp spider  is only pretending.
Countershading is another kind of camouflage, in which the top of an animal’s body is darker in colour, while its underside is lighter. For the predator, this is confusingly counterintuitive. Sunlight illuminates the top of an animal’s body and throws shadow on its belly: prey is supposed to be light-coloured on top and darker underneath. Countershading reverses this natural order and makes it harder for a predator to spot its prey and to judge its position.
A wood mouse  and a grey squirrel [10[ wearing countershading.