Question, since there is a huge amount of unobtainum in pandora's ecology, it must be part part of every creature on the moon. It is describes as a grey rock. I am just wondering could the color be partially influenced by unobtainium and used to detect possible fetal changes in the magnetic fields of Pandora and Polyphemus? Though I do agree with a planet that has light lvls around twilight it would be a good color for camo,

This may be a spoiler and it does diverge a lot from the Avatar movie, but the original script is online an one of the locations is http://james-camerons-avatar.wikia.com/wiki/Project_808#Original_880_Script alot of what happens in it I like some of it is pure schlock, but there are alot of scenes that would help flesh out the movie, and I thought you might like to see it. Remember this was written 12 years ago

Just a dumb thought, the unobtainium is blue, could this be a sensing organ in the skin f for them to sense when the magnetic field around the planet starts to fail allowing them to get out of the way before the get fried by radiation from the planet or sun. One of the discriptions in panoradedia states that magnetic field sometimes fails