"National dress" is such a strange concept to define.
The Han Chinese were the most common ethnic group among Chinese citizens on Earth before the evacuation of that planet in 2199. Now used as a slang term for Asian-descended humans, especially in the worlds of the former Eastern Bloc.
Season Eight Alternate Timeline[]
In the Middle Kingdom, Han was an official ethnic category on identity documents, as part of the Imperial government's open policy of ethnic discrimination in favor of its Asian-descended subjects.