That is a damn good question about the neonate colours, of these, and the green tree pythons, morelia viridis. Their neonates are either a shade of red or yellow. And they are pretty distantly related to the emeralds, so both of these neonate colours seemed to have come about through convergent evolution. The thoughts I have heard is that they stay lower to the ground, and with the GTP's in particular, there are people looking into weather the localities that have more red babies are from areas with more reddish leaf littler, and the localities with more yellow offspring are from areas with more yellowish leaf litter. It's a hard thing to prove apparently. But they must exist in a different specific niche in the environment. Though from what I've heard, many of the neonates in different islands and localities, (Aru, Biak, different areas of the main Papua Island, Suriname & Guyana, & along the Amazon basin, etc...) inhabit different niches, but all have the similar neonate colours. I have also read a theory that states the reason for the bright coloration may be to mimic brightly coloured vipers and other venomous small snakes.
You should ask your herpetology professor his thoughts. I would like to hear them.
As for their temperament, they have a somewhat unearned bad reputation. They are a tricky species to keep, and and even trickier species to breed successfully. SO a large majority of the animals people have are wild caught imports, mostly from the northern localities. And these tend to be a bit less friendly. They stress easily, and there are a limited number of ways that a snake can express displeasure. Add to this the phenomenon called "Emerald Regurgitation Syndrome", ERS, which is now believed to be from Psittacosis, or an infection of Chlamydophia psittaci, which is common in birds exported from the same region, and they are sometimes all held in export facilities together. This has almost always worked out to be fatal, and very easily spread between ETB's.
So if you add all that together, you have a difficult to keep species that stresses easily, with allot of fatally ill animals going around, many of which have been shipped part of the way around the world. And the successful breeders here in the states charge allot for the babies. (Some of the nicer amazon basins can go for over $15,000). The imported surinames are grumpy, and normally stressed, which makes them even more grumpy. When I got this little one, there was a guy at the same show with two beautiful imported high white northern adults, I was considering. When I asked to take them out to check them over, he handed me a hook, some gloves, and everyone behind the table gave me 10'+ Clarence, and this is a guy with venomous permits. (For the record, I was banking on the old show credo where most people keep aggressive animals cooler so they are a bit more docile.)
If you get a captive bred baby they are normally very handleable snakes. Get an imported adult, and you never know what you are going to have. If you are ever interested I can point you in the direction of some good breeders with northerns at reasonable prices. (The amazon basins are the ones that typically go for the insane money.)
And a thought on the water misting, with these, GTP's or any snakes that have the labial heat pits, (though the ones on emeralds seem to be more sensitive), if you mist cold water directly into these areas, it must be a bit of a shock. Many don't like it, even the tame ones. Try misting from above or behind the head, not straight on, or the side, so the water doesn't spray directly into the pits. Also try warm, almost hot water. The vaporizing of the water coming out of the sprayer causes it to cool quickly, and water that ends up being closer to the temperature of the snake at that time doesn't cause as much of a shock either. Also, I have heard a number of knowledgeable emerald keepers say they don't actually spray the snakes as much as the substrate most of the time. For various other health related reasons, but this being at least part of it.
