We need to know more facts about your chameleon and your husbandry before we can help you. ex. Cage size, Species, how old, lighting etc. List everything that you can think of. Also a picture will help alot.
I have a senegal chameleon, probably about 9 or 10 months old. Right now she is kept in a terrarium but i want to move her to a screened cage when she gets a bit bigger. She eats only crickets and drinks when I mist her usually. Her stool is a bit runny but isn't too yellow and has white in it always. The temp is 80-90s during the day and 70-80 at night. The humidity is kept 55-70 %.
She has been staying black or brown or greyish SO DARK of colors she used to change but not stay those colors all day long. She will turn her normal green if I hold her. I recently changed her cage set up but I tried to keep it as similar as possible for I always do this when I clean her cage.
I'm thinking about just getting her screened cage asap because there is definitely something wrong with her. SHe has changed so much
If you give her more heat in a terrarium you might cook her. I would put her in a open plastic tub if she is to small for a cage. She might be seeing her reflection in the glass and think it is anothre cham and that could be makeing her mad. Chams will also go dark when absorbing heat but because she turns back to green when you hold her makes me think she does not like it in the terrarium.