Color-Coded Patrician: Played straight with the uniform colors for each of the Ministries, the Senate, and the Curia, along with all of the runér; of course, there are no sumptuary laws rendering those colors off-limits for anyone else, but you can usually tell on any formal occasion by looking for people wearing the right kind of formal dress, then divide them up by the colors.
Bioluminescence Is Cool: And available in several varieties from your local bodysculpt clinic, along with some interesting variations on the theme of chromatophores. Ah, fashion industry, what will you bring us next?
Also used for some more practical purposes, like non-electrically dependent emergency lighting, engineered glowing trees for streetlights, detectors of this and that, etc., etc.
Sharp Dressed Man Soph: Given just how obsessive the Imperials are about their ideals of beauty and excellence, the Empire has a heck of a lot of these (although not so limited to business-suit analogs). And most of the exceptions are found among the young, who sometimes tend more towards The Dandy instead – because while obviously these things should be taken seriously – clothing, like everything else, is Serious Business – they haven’t yet quite grasped how important making it seem effortless is.
The female version is essentially equivalent (although even less limited to business-suit analogs), but the young in this case tend to trend toward The Fashionista instead.
The Dandy / The Fashionista: Common among younger Imperials, who are pursuing the cultural ideals of beauty and excellence just as hard as they can, the more so to give them weight. (Looking awesome is an aspect, if far from the entirety, of being awesome, after all.) They do eventually settle down to a consistent, personal style, though.
Awesome Anachronistic Apparel: A minor consequence of widespread immortality and independent-mindedness is that when people find a style that really fits them well – and even more often than playing any one era straight, this means “taking the bits they like from across a considerable spread of years”, like a more temporally-unfocused version of steampunk style – they tend to stick with it. However the world may move around them. A crowd of Imperials from many different generations can really be quite the kaleidoscope of anachronisms, consequentially.
Arm Cannon: Mostly reserved for fighting cybershells and ISS agents. For day-to-day wear? Apart from the impracticability… déclassé, darling.