Are his urates white? You can kind of compare urates to people, the more clear/light your pee is the more hydrated you are. Chameleons just have solid pee so it isn't see through.
I saw my Cham drinking from the cage ceiling.... I saw him stuck to the ceiling upside down and licking the remaining drops of when I misted the enclosure.
I sort of adhere to the "if I see him/her drink every other day" then it's fine as long as the poop looks good. Since they don't poop every day, it's hard to use that as a daily guide and I think it's natural for pet parents to worry about their babies daily.
I have a drip running 6 to 8 hours a day (not in a row) and mist a couple of times a day. I also just go drop water on them when they are in the right place to do so. My little female Rudis will immediately go to the drip and start drinking...my male Fischers will drink what I drop for him. I try to get a couple of droppers full into him every couple of days that way and hope that he takes advantage of the drip time he gets when people aren't in the room watching him (I check, his poop looks good, so I guess it's working).