Every tribe has their own uniuqe culture and stuff… and thus different design values.
BUT decorations / inscriptions are a universal one.
So let me show you my Early concepts for the this
The Water tribes are based on the skirt Gali wears 
And I decied on making it in that style. I really does love how iconic this looks.
The Stone tribe.
A massive and often very very simple style
Mostly for when they use it in their windows.
The Air tribe:
Often known for their simple designs they are meant to depict wind currents… so yeah it will make alot more sense to someone understanding the weather .
And last and not least the Earth tribe.
Still pushing the concepts that their temples are wonders from AGES past they read ancient scripts down filled with wisdom from a past age. Granting them Vast amounts of knowledge…
The Candle head cult we got canon looks for this konwledge. deep in the catacombs of the Temple cities.
