finally, a decent looking (well planted) xanth cage.
i agree, not a burn, imo, stress coloration, likely a warning flag of a metabolic issue. imo, probably be prudent to submit an entire help form in the health clinic. jmo
ps does this animal get outside daylight and if so, is his supp regimen adj accordingly?, just a thought.
is this color displayed most of the time, or does it seem to be related to something, like feeding, misting or being disturbed?
some dark coloration on occasion is normal, especially when disturbed or exposed to outdoor uvb for the first time in a while, but if it is displayed fairly constantly in an indoor setting, then i would be a little more concerned.
ps can he see the female or her cage?, if so that could likely have something to do with it.
it can be really hard to guess age even in person, but if i had to take a wild guess, i would say 8-12 mths. jmo