The part that always got me was that they had so many uniform changes. I know that in the real world, each show and movie basically got their own special uniforms, but it seems kind of hard to believe that say… Captain Kirk would have had what, four or so different everyday uniforms, and they were all dramatically different from each other? Picard had six over the course of his career according to Memory Alpha. That seems like a lot more than most militaries undergo in our era over the course of a career. (assuming the service dress uniform).
In the TNG epsisode “Drumhead,” a crewman being questioned during a hearing is asked why he didn’t attend the Starfleet Academy and he says something about just wanting to get out into the galaxy as quickly as possible. So they do have personnel on the Enterprise in TNG who most definitely aren’t officers.
The Federation is made up of lord knows how many different species and the various cultures within those species. I can easily imagine them making changes more frequently than what we’re accustomed to.
But do you have to attend Starfleet Academy to be in officer? In the United States Army you do not have to attend West Point to become one and I would imagine it would be the same for Starfleet.
(I have no detailed insight into the United States military, Starfleet Academy, or West Point. So please forgive me if i’m totally off base.)
Maybe Michael Meyers in space? 
Starfleet Academy seems like a universal experience for Starfleet officers though I don’t think they ever explicitly say one way or the other. When TOS originally aired, nobody really cared to ask those kinds of questions.
Starfleet Academy is the biggie (both the main SF campus and over 80 satellite campuses on other planets), but there are other pipelines to a Commission in Starfleet that are canon:
Starfleet Medical Academy - Notably, Dr. Crusher Attended.
Starfleet Technical Services Academy - also a major training pipeline for enlisted personnel (more on this later).
Vulcan Science Academy - Michael Burnham and Cmdr. Sonak are two canon characters who got their Starfleet commission through the VSA.
Civilian Federation Universities - Just as modern militaries accept officer commissions from standard universities, individuals who attend major academic institutions can seek a direct path to a Starfleet commission or enter an accelerated officer candidate program. Deanna Troi attended the University of Betazed, and Dr. McCoy graduated with a commission from Ole Miss.
As far as enlisted - The Technical Academy on Mars was the primary training institution for NCO and enlisted. According to the TNG Technical manual (considered canon) there are 575 - 680 enlisted and Non-commissioned officers, 185 - 275 officers, and 150 - 250 civilians on board a typical Galaxy Class starship.
“Non-commissioned officers” might be a more accurate description of them.
EDIT: I missed the previous post, Sorry!
One of the dumbest ideas ever, I’m glad they used it only once or twice,
GEORDIE ON THE “BATTLE BRIDGE”: Okay, guys, this is how it works. We pretend to run like a scared rabbit, put all the women and children on board the saucer section, send it off into interstellar space unescorted and at sublight speed, and pray they make contact with a species that will welcome and protect them. We then turn around and face the peril instead of continuing to retreat and hope that our truncated vessel will prevail over the enemy! Any questions?
MILES O’BRIEN: Uh, sir… What if we’re blown to smithereens, or the enemy just ignores what’s left of our ship and takes off after the saucer at warp speed? It’d be easy for them to catch it and thus guarantee a steady supply of Terran women and children to slave markets throughout the Galaxy for generations!
GEORDIE: Can they do that?!?
The old Starfleet Battles Dreadnought had a third warp nacelle for just the saucer section. Maybe one nacelle for that, another below the engineering section? Wouldn’t look as elegant but would make separation something that can make sense, vs. hanging the saucer section out to dry for the Borg or Romulans or somebody.
Of course, ALL starships should arguably be simple geometric shapes WITHOUT any skinny connecting parts which an enemy can easily blow off.
Do you have a source for this? I seem to remember reading somewhere that it was a Constitution class starship.
Aha! You just discovered the flaw in the plan! 
IIRC, Enterprise was actually passing through the Farpoint system when they did this, so the saucer section arrived at station some hours later.
Yes, this trips people up a lot. The class was Constitution, while the particular example destroyed by the Doomsday Machine was the Constellation
Oop! You’re right! My “source” is a faulty memory! LOL
Refresh my memory here: Were they under attack at the time? If so, they were lucky they were in a friendly system. That’s not always going to be the case, though.
Which is why saucer separation is an almost never used option.
But what if the colors and insignias in such a film are all wrong? How could you know? I don’t believe there are any color films of the actual war itself as I don’t think color motion-picture photography really existed then (at least outside of experiments).
I just want to mention that NTSC (the North American television broadcasting standard) is sometimes given the nickname “Never Twice the Same Color” in Europe because its reproduction of color was so inferior to the European PAL standard.
Abandoning ship usually is.
There are plenty of surviving examples around. They can all be used in designing costumes.
Yeah. I was mostly commenting on the OP saying “Watch a color film about the US Civil War” and how I don’t think there was color film during the war. And if they meant a later film you can’t know for sure that the uniform insignia is accurate.
OK, I get it. Sorry I misunderstood.
I don’t think any motion pictures, color or B&W, were made during the Civil War. Photographers like Matthew Brady were documenting the conflict with glass-plate negatives, but Eastman, Edison, and their peers wouldn’t develop the technology needed for cinema until 10–20 years later.