Overall, most things look very good.
There are just a few things that need to be changed for him to stay healthy, though.
Jackson's are very sensitive to oversupplementation.
It is recommended that dustings be light and as follows
Calcium every other feeding
Calcium with D3 once a month
Multivitamin without any D3 once a month
Excessive D3 or multivitamins leads to kidney /liver damage, which is why you will often read warnings against overdoing it with supplements.
The multivitamin I use is this one:
http://www.pangeareptile.com/store/zoo-med-reptivite.html
(The one without D3.)
Just as we need a variety of foods to stay healthy, the best cham diet includes a variety of appropriately sized feeders.
Phoenixworms, silkworms, hornworms, Dubias, Blue Bottle flies and isopods are all good additions to his diet.
My Jackson's love Blue Bottle flies.
All feeders should be fed a nutritious diet, so that they provide your cham with the most nutrients possible.
Those commercial gutloads are very convenient, but unfortunately they are low in nutrients.
This linked nutrition blog was written by a veterinarian who also keeps chameleons tells you more:
https://www.chameleonforums.com/blogs/ferretinmyshoes/560-frequently-asked-questions-nutrition.html
Some of the forum sponsors such as Mulberry farms, offer a variety of feeders.
https://www.chameleonforums.com/index.php?page=sponsors
http://www.mantisplace.com/ has both Blue Bottle fly larvae and pupae
If you add some live plants, this is a list of ones that are known to be non-toxic to chameleons:
http://www.flchams.com/safe_plant_list.asp
Any live plant should be washed with dish soap and water to remove pesticides and fertilizer residues, followed by thorough rinsing---because chams drink off the leaves.
Hopefully, you already have enough leaf cover for him to feel secure.
Chams do turn a lighter color when they're asleep.
Sometimes Jackson's will turn a darker color when they bask and it does take a week or two to settle in when things are set up right..
Providing them with enough water is essential, so it is good that you have a dripper and are misting.
Some Jackson's don't drink until they're misted for about 5 minutes.
You'll know that he is hydrated enough when his fresh urates are snowy white.
Yellow, pink or orange urates indicate that more water is needed.
You'll find additional reliable info here:
https://www.chameleonforums.com/care/caresheets/jacksons/