Is the color change of chameleon-like creatures voluntary or involuntary?

Color change in chameleons has functions in camouflage, but most commonly in social signaling and in reactions to temperature and other conditions. The relative importance of these functions varies with the circumstances, as well as the species. Color change signals a chameleon's physiological condition and intentions to other chameleons. Chameleons tend to show brighter colors when displaying aggressively to other chameleons,[17] and darker colors when they submit or "give up"