I'm very glad that you've posted the requested info and pics.
Most of your care looks great.
There are only 3 things that I'd suggest you change.
The first is to make sure that his basking spot itself is not too hot. 75-80 is good for Jackson's younger than 9 months.
A 60 watt bulb in a combination fixture might be making it too hot to bask--and Jackson's do love to bask!
A 40 watt regular incandescent bulb might make the basking area temperature better for him--but you have to check the spot, preferably with a digital infrared thermometer.
The second thing is that he would likely benefit from longer mistings and the addition of a dripper.
A dripper can be as simple as an empty milk jug with a pinhole poked through the bottom.
The calcium without D3 is very good but he will also need to have calcium with D3 1x once every month to 6 weeks and a multivitamin once a month to 6 weeks.
Jackson's are montane chams and can't be supplemented as much as Panther or Veiled and other non-montane species of chams when it comes to D3 and multivitamins.
many Jackson's keepers only use the plain calcium for every other feeding and you want to be sure the dusting is light, rather than feeding your cham ghostly, frosted bugs.
Lastly, if he is 3 months old, then there isn't anything wrong with his colors.
Jackson's have baby colors and don't change to adult colors until somewhere around 4-5 months of age.
Please have a look at this forum caresheet for some more good info and be aware that on the left of the linked page, there are links to other pages about things like feeding, watering and general cham FAQs:
https://www.chameleonforums.com/care/caresheets/jacksons/