I can't answer your first question exactly, but in a good environment with balanced foods he should colour up.
To explain "territory" and "territorial" a bit. What area a particular fish views as its territory can depend upon not only the size of the tank but how it is aquascaped. Breaking up a tank's visual length with wood and/or plants sometimes creates smaller areas that a particular fish may view as his territory. But another fish might view the entire tank as his territory. This is very common with angelfish; within a group of 5, one male will be dominant and consider the tank as his space. He may or may not tolerate another male anywhere in the tank. Unless the tank is very large, say 8+ feet in length, this fish might always regard the entire space as "his." Gourami are very similar. Usually breaking up the space helps, and keeps aggression minimal. But remember that in the wild the dominant male can basically own the stream, and other males will likely simply swim off. That isn't possible in the aquarium, and fish secrete pheromones or chemical signals, so even when no physical contact is made, the fish are still interacting and the subdominant males know the dominant is there. And individual fish can be more or less territorial, just as different dogs of the same species can be more or less "friendly." It's all part of nature's wonder.