"A lot of people are led to believe that chameleons change color to blend in with their surroundings but that isn't true they are born with a coloration to blend in with their environment, thats why most chameleons are green to blend in with the leaves high in the canopy of a tree where they live."
...and as stated, chameleons are colored the way they are due to their environment, as seen in the first example, a very rare Kilauea lava chameleon. You should see it when it gets brighter and wants to scare off intruders. (No, don't worry, they do not breath fire in captivity.)