Ok I didn't know where to start so I thought the easiest way would be to just copy your form and add my thoughts in red. So here it goes:
Your Chameleon: Veiled Chameleon, Male, 12 months old, the person I bought him from said this is how long it takes for them to grow up but he is still shedding often so this must not be true. He has been in my care since he was about a month old. He is probably ready for his big boy enclosure, so if you are going to build it you should start now
Handling: Once or twice weekly, mainly to check if his jaw and legs are rubbery and if there are any mites. I do it quickly because he hates getting picked up and I feel bad for him because he looks so scared. Why are you doing this? Does your cham already have MBD or are you just checking every week. How are you picking him up? Just reaching in and grabbing him? He could be dark colors all the time because every time he sees you he thinks you are going to take him out and check him over. It sounds like there is no trust there at all. I don't blame your cham, I would be stressed and freaked out all the time to!
Feeding: He mainly eats adult crickets gut-loaded with calcium, spinach, apple, and orange, sometimes he is fed waxworms and rarely mealworms. You need more verity of Feeders, and no mealworms (use superworms instead), and you need to research gutloading you shouldn't need to gutload with calcium and spinach is a no no! There are countless threads, posts, and blogs about gutloading.
The food is dusted with a D3-free calcium supplement three times weekly. I do D3 free because I've read that if given D3 supplements along with exposure to proper UVB they will get sick from too much of it. You need to throw all that out the window! A good supplement schedule is: calcium w/o D3 every day of the week except 1. On the day you choose alternate between calcium with D3 and a good multivitamin.
Watering: He is sprayed twice a day with a full reptile mister of lukewarm tap water and a '' dripper '' ( a plastic spring water container with a small hole in the bottom ) is placed on top of his terrarium once every morning. Humidity is about 40-70%. I would add at least 1 more misting session, preferably 2
Feces: Recent droppings are black, urates white. He has never been tested for parasites. You should have him tested at least 2 times a year
History: About a year old. Purchased from LLL Reptile at an expo. I know that's not the best, but I didn't want a pet store one because they are treated horribly and my parents wouldn't let me order one online because they said the chameleon would get stressed, though I figure an expo one would be WAY more freaked out because of all the people..He slowly changed from bright green ( neonate ) to green and brown ( juvenile ), to brown and bluish green ( older juvenile to now ). See comment above
Cage Info:
Cage Type: Zoo Med 18, by 18, by 36 screen cage. I plan to build or buy a larger one when he becomes around 16 inches long. See comment above
Lighting: Zoo Med Reptisun 5.0 Tropical UVB. On twelve hours a day, about six inches about basking branch. As asked above, how old is the bulb? If the light passes through a screen go with a 10.0. remember that nothing beats natural uvb so research "taming" so it is not too stressful for him, maybe work on it over the winter so when next summer comes you can take him outside
Temperature: Basking spot is 85 to 90, takes a bit to warm up in the morning, as shown in some of the pics. Rest of tank is around 80. Lowest night temperature is 75, highest 80. I measure it via Zoo Med thermometers. One is at the basking spot, one is near the bottom.
Humidity: 40 to 70. Maintained via dripper and spray bottle. I keep track of it with a hydrometer.
No live plants. I had a ficus when he was little, but the frequent spraying killed it. I might get another, but if so I would cover the pot with mesh to keep water mostly out. The tank is filled with plastic vines and there are silk plants attached to his branches. Veild chams like to eat plants sometimes, he needs live plants! Pothos work great! There are countless blogs about safe live plants you can use just do a search and find what works best for you.
His cage is located next to my African Sideneck Turtle, and both of them are in my room. The turtle and him watch eachother, and I'm sure she would eat my chameleon if he fell in, but I don't think the turtle stresses him. I am located in western Washington state. Move his enclosure or make it so they can't see each other. It may help.
He has been brown and greenish blue most of his life, and I always thought it was just to blend in because he was healthy, active, and ate lots. Recently though, he stopped eating, which could be because of temperature, or shedding, or pickiness, but I am sort of worried. His eyes are also not as puffed out as many chameleons in pictures I see, so the loss of appetite might be because he is a little thirsty. I'm worried cause they can mask illness for a long time before they get too weak to show it. Are the adjustments medical or to do with his habitat/care? Please help because I am very worried.
I am also very confused about what kind of enclosure he is in. In a few places you said"tank" or"terrarium", but in the cage information you said "screen". Could you please clarify.
Those are my suggestions to do some are asap and some will take some time. Once you have made those asap changes wait a few days and see how it goes, then repost an updated form so we can see how your doing. And as always we are always here to help so if you have more questions or something changes not for the better feel free to post/ask!