When I got my panther chameleon from Kammers they told me about this special dust to put on your chameleon food that can go on every feeding and it has the right vitamins your chameleon needs. It helps a lot of you forget to dust wth D3. I highly reccomend you get it. Here is a link below...
My panther also does that sometimes when he is basking. It is a way for them to release heat when they get to hot if he does it more then 2 times a day it might be something to worry about. I'm not an expert so I will let more experienced people come in.
My panther chameleon ghost does have a lot of lighter colors when he is sleeping. He is 4 1/2 months old and is showing amazing color during the day like red, green, blue, and a tiny bit of yellow. I think it shouldn't be a problem since ghost turns a lot more yellow when sleeping.
They are looking really good! are you going to put anything on the wood? If you do be sure the smell is gone before the chameleons in. I know you're the expert, but you have to make sure the smell is gone.