my male Vieled chameleon is digging a hole.

[Diebend]

Do you have live plants in the cage for him? He will eat them, as well as they will help to raise the humidity and keep it stabilized. How big is your enclosure? I would spray AT LEAST twice a day especially during the winter months. The furnace will dry the air fast. The dull brownish green color that he is, in the picture signals to me that something is wrong. Humidity is generally the most common issue, so start there. And I agree with more food, too. Keep those pictures coming!

I have no furnace. I live in central America , the winter isn't harsh here and it is sort of a humid place.
The enclosure is about 45 inches high by about 25 inches wide. I have 3 live plants and 1 fake wich was a gift so I have it hanging from a corner.

 

[Diebend]

Here is a pic of him when I take him outside to his tree. I always thought he had that brownish color cuz he mostly likes to be in the part of his cage with almost no vegetation.
Here in the tree he has a brighter green color.

 

[Angelwolf]

Bright green is good. That means they are happy and relaxed. Green with dark spots is a warning to back off. And dull brown/gray is usually either stress or illness. They don't change color for camouflage. They change to communicate. So if he's usually brown and dull, he's telling you he's unhappy in some way.

 

[Angelwolf]

By the way, someone had posted a link to an old thread, regarding a "male" veiled who was digging, and it turned out actually being a female in a boy-cham's clothes with spurs and everything, but she was egg bound and ended up dying because of it. So if your cham continues to dig, get him to a vet FAST and have them do an X-ray. You can't trust palpation, either.