I have had a veiled Cham for about 9 months...about a month ago I noticed that he was a dark brown all day. It has been like that for a long time..he still has pattern and walks around everywhere..he drinks plenty of water..abd eats every day. He has the proper lighting and lives comfortably in a 50 inch tall cage. 36 wide and 25 deep..I have a mist system and an aranyment of 7 different plants..he is very well looked after..I just wish he had more color..if some one could please help that would be great!!!