Cos most animals are actually pretty bad at colour perception. The goal of camouflage in a complex environment like a jungle is to break up the outline of the animal, rather than disguise its colouration. That’s why every camouflaged animal, including fighter humans, have complex patterns like spots, stripes or khaki. You’re not going to find a bright pink leopard, but an orange leopard with a lot of black and white spots is actually a lot harder to perceive as an individual animal than an entirely green leopard.
Also, green is a surprisingly rare colour in nature (even plants only evolved green once and every single plant today has inherited it from that one ancestor). It’s only evolved when it provides a significant evolutionary benefit over any other colour. For animals that live in the shade, like most ambush predators, just some dark colour does the job.
There are a lot of green animals living in forests and jungles. However there are two main reasons why there are not more such animals. Firstly the most common color pigment in animals is melanin. This is a group of pigments that produce colors such as black, brown, red and yellow but no green. In fact there are very few biological substances that are green at all. So it would be a very rare mutation to cause an animal to turn green. The second reason is that the jungle floor where most animals live is very dark and brown. Most of the light is getting caught by the leaves in the canopy above and very little light actually filters down to the jungle floor. So a black or brown creature would not be out of place as it would just look like a shadow or a piece of a tree. However a green creature would often be very distinct from anything else, even the little vegetation on the jungle floor have different color and shape then what animals are able to replicate.
Partly because camo matters a lot more in the open plains and ice fields of the arctic than it does in dense jungle foliage. In a jungle, you’re hidden by vines and leaves and tree trunks much more than you’re hidden by your coloration.
That said, some jungle animals, like jaguars, *do* have camouflage, but it isn’t green. Instead, it’s usually a mottled pattern of dark and light spots that mimics the patchy distribution of sunlight that reaches the floor of a dense forest. The main visual pattern of a jungle is light and shadow, not one solid color; a jungle floor has various shades of green and brown. Try to find a solid color that blends in with [this image](https://en.wikipedia.org/wiki/Rainforest#/media/File:Forest_in_the_bluemountains.jpg), for example.
Animals see different wave lengths of light than the human eye sees.
The colors we see are not necessarily what the inhabitants of the jungle(this applies to all life on earth) see.
Patterns that evolved are based on what worked in making species successful in mating, hunting or eluding predation.
In fact there are patterns visible in other wavelengths we are just discovering.
Latest Answers