A light at night will probably make him more tired.......Chameleons need darkness to sleep properly. Even with his eyes closed he has a parietal third eye on top of his head which can detect the red light and might disturb sleep. A nighttime drop in temps is good for his metabolism. If it gets any lower than 60F you might want to get a ceramic heater or somehow heat the room up to 60. He looks great though, congrats