Waterbender: Katara

Water tribe design is one of the most coherent costume systems in animation, and it holds together because everything in it is practical first.

Fur where the cold gets in. Hide where the water does. Layers that can come off. Blue because that is what the dye available would have made. Bone and shell as the only ornament, because those are what is to hand. Every decorative choice is downstream of a practical one, which is why it looks like a real culture rather than a colour scheme.

Style it that way and it works. Add something that would not survive the climate and the whole thing falls apart.