My lizard turned a stange dark green/sorta black today. After I noticed it I cleaned her cage (she is in an aquarium for now) and made sure the water was clean and now she is hiding (it is night). The guy at the pet store thought it was just stress - but I am nervous. She has heat lights and UVB but I think that I gave her too many crickets and they died and fouled the water. Could I have hurt her? Should I just watch her color tomorrow. Do they get dark under stress or could she be sick. It happened so fast. I am a new lizard owner - my daughter left for college and I have become a lizard lover.