Is it appropriate to confront a higher rank when they are blatantly disregarding regs?

With tact and professionalism, absolutly ok.. though I would do so as a question not a confrontational remark.
Afternoon Sergeant, if I may ask a question?.. I thought makeup that was not complimenting natural skin tone or was contrasting natural skin tone was against regulations.. Did I ready the regulation wrong? While looking at my smart phone that I have opend AR 670-1 on

I did. I was a sergeant major in the Marines who “grew up” in the infantry and Reconnaissance. I was sent to the air wing to be the squadron sergeant major for a helicopter unit when promoted to that grade. It was a culture shock, to say the least. Many times I corrected lieutenants, captains, and majors who were wearing the uniform wrong, particularly flight suits and flight jackets. I approached them respectfully and asked them for their help in setting the example for their junior Marines, particularly aircrew. None of them brought up the difference in grade, or gaffed me off. If done in a respectful manner, in the spirit of setting the example, it shouldn’t be a problem.

The key is to be respectful, discrete, and direct. You will never know what they were thinking prior to seeing you. Do Not Embarrass or talk down to them. There was a morning on a carrier when I accidentally had on a shirt with only one collar device. A sailor calmly pointed out the miscue. I certainly thanked him. Stuff Happens.

Yes. I did as a Drill Instructor, the officer had his hands in his pockets. I approached him, saluted and asked, how was I to instruct the trainees when he was disregarding the rules. He immediately understood, case closed.

Someone with more rank could have questioned her SUPERVISOR...

Yes I did it in Afghanistan in 2012. An Afghanistan soldier drove a bulldozer over a septic tank and it fell in. I was ordered to get it out and I told the chain of command with all due respect no sir.

Ha! I’m a old old old army retired Vietnam vet. When you were still State side you wouldn’t see anything like that period. When in country that changed, all spit and shine we’re gone. Rank mattered but only if they deserved it, not how they dressed. Just saying for what that’s worth

It’s a good question! In my experience I remember attending BOLC II Army OCS in Oklahoma when I was confronted by a female captain who felt my hair was too long. I had just gotten a fresh haircut the day before, she chastised the SHIT out of me in front of my peers in a demeaning and belittling way. I swear I looked squared away and was in regulation, I could only assume her criticism came from the fact I wasn’t wearing a “ High & Tight “ which was NOT! Mandatory.
I maintained my military bearing as a 2nd LT. Being confronted by a Captain.
Regardless, she was an African American Female Soldier with “ Blonde “ highlights in her hair ( FUCKING BLONDE!) No kidding.
I responded, “ Mam, your hair is longer than mine...” she started to fume! & responded, “ I am a female Soldier!...” my response was “ ONE TEAM ONE FIGHT MAM...” at this point she commanded “ Square yourself away LT!...” I responded
“ Yes Mam, as soon as you take care of those highlights.” Words cannot express the look on her face, she didn’t know weather to SHIT, or GO BLIND!
Most service members will not win the battle of right and wrong between a superior and self.
Lessons I learned from this are many and perhaps from hearing this unbelievably true antidote you can benefit a little from another service member’s experience.
One of the things I learned in this situation is a superior, regardless of rank, Officer or Enlised, will pull rank on you and try and justify their position.
Do you really want the situation addressed?
Don’t confront the UNSAT, leader, request mass to the persons immediate supervisor and report the incident.
If a leader is arrogant enough to break regulations, I promise you they will be arrogant enough to defend their “UNSAT ESS...” But do you really want accountability and a change for what is proper?
The answer is not in confronting the culprit but “ REPORTING “ them.
Case in point the “ Black lipstick “ don’t even try to confront the situation, it’s a loosing battle, but reporting that superior would not only be appropriate but effective.
I shared my experience not to provoke your response or motivate you to respond a certain way should something like this ever occur again, but to provide an understanding of my experience in a similar situation.
In short , “ How do you deal with this situation?”... REPORT!!!! Don’t confront.
Good luck

Many year ago me as an SSG and a WO were returning to Ft. Bliss from a TDY. There was a LTC with material clearly marked as "secret" out and open on his tray table. Hey got really upset when I tactfully suggested that material should not be open for anyone the aircraft to see and started berating me. The WO I was traveling with came to my defense and calmly suggested that if the LTC insisted on compromising classified material he could have the flight crew radio ahead and have some MPs meet us at the gate. He put the stuff away.

It's also interesting to confront a person when you're retired. I was in an auto parts store and one of the clerks, an A1C who must have been working a part-time job, was wearing her AF fleece jacket with her nametapes and rank still attached (she was wearing civilian clothes with the jacket). If I'd been on active duty, I'd have had a senior NCO moment with her. But I'm not, so I said, "You might want to take off those nametapes and your rank before someone on active duty comes in here and has a word with you." And I left. Wasn't much else I could do.