Can chamelions turn all colors

The main reason for a change of color is not camouflage, but rather as a means of communication. Chameleons change color to communicate with others of their own species. For example: Let's say that a male's sweetheart is sitting on a branch somewhere. He crawls over to her and starts changing colors and flaunting his stuff. Then, a rival male comes along and starts making a move on her. The first male gets mad and turns a dark shade of black to show that he means business. Then the other male follows and this display continues until one of the males get scared off, and the winner gets the gal. Also, another reason could be to maintain temperature control.

Chameleons change colour to hunt too.