See, if you guys would just adopt barrister’s robes, you’d save yourselves a lot of trouble. 
Fellow 1-L here. We had our Freshman Moot Court Competition before the graded oral arguments, wihch was nice since we got some practice in. It was a double-elimination tournament; my partner and I argued four times before losing our second one (a record with which I am perfectly happy).
I wore my gray suit, blue shirt, and red tie all four times. No one noticed, as far as I know. Or maybe they’re all aware that I’m a fashion disaster and were just being polite. Either way is fine with me.
If you’re interested, our hypo was a guy caught at night outside a Federal Reserve Bank (but inside the perimeter fence), hiding in a dumpster with crudely drawn plans for a break-in and a gun. He was a prior felon, and my issue was whether his being a felon in possession of a firearm counts as a “crime of violence” under the 1984 Bail Reform Act, and is thus sufficient to trigger a detention hearing to consider whether to deny bail. We weren’t told what his predicate felony was; the issue here is whether felon-in-possession is itself a crime of violence. Interesting stuff, I thought.
My partner’s issue was that the prosecution drew up the indictment wrong, forgetting to include a charge of “attempted breaking and entering” with the charge of actual breaking and entering. Since he was caught outside the building, my partner (representing the government) had to argue that it wasn’t a fatal flaw in the indictment.
Whee!
I had a professor in law school, notoriously crazy as the proverbial shithouse mouse, who argued a case (and ultimately won) before the U.S. Supreme Court in a tuxedo. I’m talking full on satin lapels and bow tie “Bond, James Bond” tuxedo. I think he handwrote his brief, too. I saw a video and it was awe inspiring. The Honorable Court must have been dumbfounded. 
My goodness.
In Virginia’s criminal courts - especially the General District Court, which is the court of original jurisidiction for misdemeanors and the place for probable cause and bond hearings for felony cases - it’s not unusual to see defense lawyers in sports coats rather than suits.
Circuit courts - trial courts for felonies and de novo appeals from misdemeanor and traffic cases - generally saw suits, although no one would cavil at a brown suit.
Argument in front of the Court of Appeals was about the first level in which I might question a brown suit.
I have to dress better now, in the government contracting world, than I did then.
I’m a staff attorney, so I don’t interact with the public or appear in court at all. I have a good charcoal suit, a brown suit that was a hand-me-down from my father (although I got it altered to fit me and it still looks professional, IMO), and a black pinstriped double-breasted suit that I consider a bit too “gangsterish” to wear to work. That one was a holdover from my swingin’ sax player days. I also have a black sport coat and an indigo (not navy) sport coat that I often wear with black or khaki slacks. Nobody has ever complained about my work clothes, and I’ve actually gotten a few compliments on my shirt/tie combinations. If you wear nice shirts and ties, that’s the key to pulling off any outfit.
I should note that when I did my clinic with the Office of the State Attorney, those guys wore navy blazers, white shirts, and khakis a lot more often than they wore suits, and they appeared in court on a daily basis. But this was in a smaller town, and these were mostly the traffic and misdemeanor prosecutors.