Everyone wearing the purple/white uniform in TNG was a civilian (as far as I know).
Edit:
https://memory-alpha.fandom.com/wiki/Starfleet_uniform_(2350s-2370s)#Civilian_uniform
It's hard for me to say if those scientists and starbase technicians are civilian contractors or simply another branch of Starfleet service. There
is a different costume right below those on the Memory Alpha page that is specifically identified as a
civilian uniform, though. In either case, as Timo points out, it does seem strange that civilians would
have a uniform to begin with. I suppose it could make some sense if they wore a uniform when working as subcontractors to Starfleet
on Starfleet bases, so that they might be easily identified when moving about.
The only example I can think of is Deep Space Station K-7 in TOS which seemed to be a wholly civilian operated facility.
That's true. It was constructed by Starfleet, but seems to be entirely managed by civilians -merchants, administrators, and technicians alike. I know a few deep space stations have been mentioned throughout the years, but as far as I can recall we've only seen K-7 and Deep Space Nine (which is an example outside of the norm, surely, given the circumstances.) Given that, do we know enough to know if this is normal or not?
..of course there would be civilian stations and outposts for research, trade or cargo transferral, perhaps even a few maintenance and refuelling space ports, though I'd suspect they wouldn't be to the same scale as Starfleet facilities.....It's really a shame there's been little focus on civvies in space in Trek, people who choose to go out into the dangerous and unknown cosmos without the backup and resources of Starfleet.
I imagine that there would be civilian installations somewhere, for trade, cargo, and maintenance if nothing else. It's just so rare that we see anything more than the Starfleet side of things, especially when it comes to humanity. I don't object to that particularly because I enjoy the stories we've seen (at least most of them until recent times), and it makes sense to focus on Starfleet, but it does leave a big gap in our knowledge base, and I would absolutely love to see a civilian focused
Star Trek series. I've actually had a few concepts in that regard myself, meant for tabletop roleplaying.
Solas, which is about a merchant (played by Jeffrey Dean Morgan in my head) who lost his wife in a terrorist bombing in the Cardassian DMZ and is struggling to keep his crew going through hard times that push his moral limits.
Frontiers, which is about a mix of Starfleet rookies (aboard the about to be decommissioned
U.S.S. Earhart) and civilian archaeologists, engineers, and scientists uncovering the mysteries of an ancient alien space station that has been colonized by a group of Gamma Quadrant refugees.
Brave New World, which is about a new colony established in the depths of non-Federation controlled space, far beyond the reach of easy assistance.
Odyssey, which follows a group of civilians who awaken aboard an alien starship with no idea how they got there, why they were taken, or how to get home - a concept which has since appeared on
Dark Matter from what I hear.
Obviously I like the idea of focusing on some civilians. A bit.
The Vico and The Raven were both civilian ships. Stands to reason there would be civilian stations.
Civilians can, of course, own their own starships and do what they wish with them. This doesn't necessarily equate to civilian managed space stations, survey stations, relay stations, etcetera.
People in such uniforms do operate ships that have the Starfleet arrowhead on the hull or say "USS Name" on the displays... Even if not actual soldiers, they might be on Starfleet employ somehow, and merely dressing casually.
Although they aren't. Dressing casually, that is. Being in uniform is suggestive enough, I'd think - perhaps this attire denotes the mysterious UESPA, an apparent "Agency" that does "Space Probing" or perhaps "Science Probing" in some sort of close cooperation with Starfleet? The civilian researchers might come from many fields of life, but would be expected to wear uniforms and bow to Starfleet-related bosses in a straightforward hierarchy of unknown specifics.
I think this is likely the case, that those who wear these uniforms are likely either from a different branch of Starfleet (which we do hear reference to with Starfleet Operations, Starfleet Medical, etcetera) or are essentially contracting out to them, meaning they're expected to wear specific clothes and follow specific rules while they're doing so.
