I will attempt to re-iterate a point I was trying to get across earlier: You speak as if you, personally, know what everyone wants, and that even the option, as a few on this thread have suggested, of having new outfits, is impossible. Mercs rarely wear the undersuits alone, as they are given voidsuits, and the potential to buy things with TC. In fact, the regular undersuit is literally just the tacticool turtleneck, with which seemingly no one had issue with before. I don't understand why someone who's attempting to preform aggressive, antagonistic ops would wear bright flashy colors in space, where they'd easily be shot to hell and back. The "sci-fi" military dress you attempted to showcase earlier would not be worn into combat, and the image of the rebels hails from old 70s-80s comics. Go look at rogue one to see how even starwars has shown attention to detail on the asthetic changes, especially when it comes to moving away from those god-awful sallets.
I could see if you wanted to add armbands or something similar to denote faction, like how we have medallions on the legion, but scifi can be flashy without insinuating illogicality in purpose. I look to halo in this regard, specifically at noble team, who managed to use saturated colors and not look goofy as all hell. The covenant were flashy because the things they wore were largely ceremonial in regard and they could hide simply by using active camouflage if they *really* wanted to be stealthy.
However. I shall admit. I am partial to decorative shoulder padding, though I'm primarily a "function over form" addict when it comes to any group who'd primarily exist in constant combat. I think that contrasts plenty with the flashiness of the station itself.