its a bad idea to mist your chameleon within two hours of lights out so make sure you get your heavy misting in late, but before that mark so your guy is properly hydrated going into the next light cycle
It is my opinion that the animal needs time to completely dry out after the last misting of the day before the lights go out.
This has been my practice and my animals are well hydrated and have never suffered from URI, bacterial infections, or any similar malady*.
-Brad
*note that my practical time in this hobby will only be 2 years this fall