Contrary to popular belief, chameleons do not usually adjust their colour specifically to blend into their surroundings. Most colour changes are thought to be involved in identification of species types and in social displays.
Chameleons are quite difficult to detect in the wild under any circumstances.
This, coupled with the fact that they can change colour, has probably led to the myth that chameleons can change colour to match their surroundings. The normal colour of many chameleons is a cryptic green-brown. A further trick is the chameleon's walk, which mimics leaves moving in the wind. They move very slowly and each time a foot is lifted off the branch their body sways gently as if rocked by air currents. Blind chameleons could still change colour as long as their mechanisms for colour change remained intact.