He looks great--overall he looks nice and healthy.
You have lots of leaves for hiding, which is good and he is obviously eating--another good sign.
If you make sure that he stays hydrated, is kept in the temperature range he needs (lower than Veileds, etc.) and are careful to feed him a varied diet of gutloaded insects without overdoing it on the supplements (Jackson's can only handle about 1/2 as much supplement dusting as Veileds and Panthers), then he should have a nice healthy life with you.
It is normal for chams to be a lighter color when they sleep.
He looks like he will have a nice darker green head and lighter green body.
A very handsome fellow!
Have a look at this caresheet for some more info:
https://www.chameleonforums.com/care/caresheets/jacksons/
Blue Bottle flies, Phoenixworms, silkworms, crickets, hornworms, Dubias and even a few superworms can all be parts of his diet.
When you take him outside, be aware that you can't leave him alone for even a minute. Birds, cats and other predators find chams tasty plus they can walk away very quickly when you're not looking.
Natural sunlight is great for chams. Some people have an outdoor enclosure with sturdier wire on the outside to allow their chams to sun safely.
