The primary purpose of color change has been found to be due to social signalling, as opposed to camouflage, although both social signalling color change, and color change for purposes of camouflage do occur in most chameleons, to some extent. Color change is also used as an expression of the physiological condition of the lizard, and as a social indicator to other chameleons. Research suggests that social signaling was the primary driving force behind the evolution of color change, and that camouflage evolved as a secondary concern.[9][10] Chameleons tend to show darker colors when angered, or attempting to scare or intimidate others, and males show lighter, multi-colored patterns when courting females.
Some varieties of chameleon—such as the Smith's dwarf chameleon—use their color-changing ability to blend in with their surroundings, as an effective form of camouflage.[11]