I ALWAYS do research before obtaining a new species of critter that I've never had or thinking about getting soon. However, I think, this time I didn't really do enough research and looking for some opinions.

I bought Smeagol (Phyllomedusa sauvagei) about 4 months ago and I don't think I have him properly set up. When I first got him he was bright green and active and readily ate both crickets & roaches. Now, he doesn't seem too interested in eating at all and this worries me. He has turned a dull green color thes past two days and through a little research it seems that he is unhappy/stressed. He pretty much sits in one spot ALL day which is under his heating lamp, which I'm thinking maybe isn't hot enough for him? It gets in the high 70s to low 80s, and I've read that they can tolerate temperatures up in the 100s. The bulb is just a 60W incandescent house bulb. I've also read that any sort of humidity what-so-ever can easily cause them bacterial infections since this species does not take kindly to humidity like most species of frogs, so I have him in a 16" x 16" x 20" Repti-Breeze which is an all screen cage. Do you think maybe this size is too big?? I've read they can be kept in a 20 to 30 gallon tank fine. If I did my calculation correct then his sized enclosure comes out to be about 22 gallons, so maybe not too big? Doing a little more Googling I've found some care sheets that say that UVB light is required, even though they are a nocturnal species. Is there any truth to this? I have his enclosure decorated minimally: He has a large piece of spider wood to climb on, fake vines wrapped around the spider wood to make it look a little prettier, and a large water dish for him to soak in (I've seem him soak in it at night a time or two). There's no substrate in the bottom - just my preference and it makes it easier to clean the enclosure. The bottom is just plastic - what came with the repti-breeze for the bottom.

I'm really worried since Smeagol's recent color change. I'm probably being paranoid and probably have figured out my own mistakes, but just looking for a little guidance.