To be honest, the indoor cage (16x16x36) is too small for this size of a panther male. The panther females we keep are in 18x24x36 and the males are in 24x24x48 - if that gives you some idea.
We do not use 100 watt heat bulbs for basking. We use regular light bulbs - the hottest being 75 watt - average is 60 watt. For montane species, we use 40 watt. The ambient temperature of the lowland cham rooms ranges from 70-80F.
You mentioned a length, most people measure snout to vent - but you didn't say if that was including the tail, so I was guessing. Our biggest male sambava was 17.5" overall and 242 grams by 2 years old. Our younger males (currently both at a year) are not quite as large. Most panther males continue to grow until they are 2.
Male sambavas usually stay in green/blue tones when just lolling about. They only color up to brilliant tones of yellows/oranges/maroons when encountering another male panther or when mating. Mating colors are different than territorial defense colors - of course. Since chameleons communicate by color - the males defending territory when encountering another male exhibit the brightest colors.
Feeding... you might want to cut back on meal worms and superworms and offer silksworms. Also - our panthers love waxworms as treats - all are handfed these tiny "candies". We offer roaches, crickets and silkworms as the staple diet for our chameleons. We have found too many problems with the mealworms, and the superworms too. If you need more details on that, email us offlist.
What we do is not what the average "cham owner" with 1 or 2 chameleons does. We have hundreds of animals and we have observed them for years. I always find that when male panthers do not exhibit "normal" coloration (happy colors), that there is something wrong in their environment. We have one ambanja male (wc) that was outfitted with 4 different cages before he finally settled in. With captive bred it is usually easier... but we don't know what they were previously used to, if we just got them - so ask the folks you got him from, if he is a recent purchase. They might have had different plants or something.
Hope this helps some,
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