We can already see how the various minions of the Empire dress, when we look at the various faction representatives we meet and talk to at Imperial-run facilities. Particularly Patronages, as they represent people living by "core Imperial values". I don't know what the bottom-rung peons who handle contact with the enemies of the Empire look like as I've never offended an Empire faction sufficiently to see them, but I imagine they're not entirely unlike how the various minor officials at Imperial-controlled stations look, though their militaristic slant is probably skewed by having military-aligned jobs.
The mid-level operatives who manage your affairs when you're Neutral look like this: top pic is a Station greeter, bottom pic is a travel consultant.
The so-upper-crust-they're-crunchy ruling castes tend to look more like these governors of Imperial Patronages:
Analysis: I don't know if it's a temporary fad or a more permanent cultural motif, but filigree work, fancy braids and enormous flared high collars are "in". The patterning and precious-metallicity of the collar and the width of the braid stripe presumably tells you at a glance the person's stratum in society. The colours and patterns of their clothing probably also convey meaning as to the mesh of patrons and cliens they are a part of. I've noticed those big loops and rings on the collar-tips of Imperial Corporate leaders too, for example.
These are of course "work clothes", worn by people who are on the clock as the public face of the local branch of the Empire. For private attire, when going out on a date or to a party or what have you, they're probably a lot more ostentateous in their display of wealth (I'm thinking "more gold chain than Mr T"), and much more subtle in their broadcasting of caste and affiliation.