Is it okay to wear my dress blues to prom?

You would adapt it as you would for wear at a ball. Although in your case, your uniform probably looks like that already. If you have a unit, remove unit insignias from the shoulders, swap the tie for a bow tie, and remove the headgear.

Looks like the Tribe has voted to have at it. Just remember that because you'll look different, the range of responses are on a bell curve. Most won't care. Some will think it's great. One or two may get into your face. I recall wearing my uniform to HS reunions. Year 5 an O-1; year 10 an O-3; year 15 an O-4. There was this other guy who wore his uniform and was the same rank as I every time.... until; year 20 an O-5 and year 25 an O-6. Interesting thing was the other guy went terminal at O-4 so he stopped wanting to talk to me. Like I say, the uniform will cause opinions to be formed and results will vary.

AR 670-1 will cover the wear and appearance of your uniform, to include when it is appropriate to wear your dress uniform outside of military functions. Off the cuff, a prom is a formal occasion, and you can wear the uniform to formal occasions, such as funerals, weddings, or any other social event that requires formal attire. The only requirement is that the uniform be worn in accordance with the specified regulation, do not mix dress medals with ribbons, be clean shaven etc etc. Good luck and I pity the other chaps when you show up. A sharp looking young lad in a sharp looking uniform will definitely be appreciated by the fairer sex.

1 correction, you cannot wear any uniform to any event that is political related, as the Services are Apolitical in nature and cannot be seen as endorsing or promoting any political party, ideology, or cause, regardless if the occasion is formal.