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

Well, it sounds like it's airforce so she's probly fine the way she is.

Absolutely, when you mention it, ask the senior ranking NCO if you might have a word with her in private. Your superior is not supposed to call you down in front of your pears, and the same should go for your "helping" your superior. I am assuming that you are female and this is fine for you to do this, if you are male, find a female NCO that can council the SSGT. I had an Afican American A1C that was wearing a nose ring with her uniform in the office. I checked the regs (at the time, AFR 30-30) and the reg called for the ear ring to be discreet, but didn't state that the ear ring must also be worn in the ear (thus the name). I went to a black female MSGT and asked what she though? Her answer was, "Say what! Let me take care of it." The problem was solved in about 3 minutes and no one was overtly chastised. Sometimes the soft sell works even better than the raised voice. Sometimes these things happen out of ignorance vs. blatent antagonism. Think about how a creditor works, and they do not send the first overdue notice as the "hard sell".

Loyalty is telling the boss what he needs to hear, not what he wants to hear.
Juniors but be warry and respectful of doing this. As a E-6, I pointed out to my 0-3 boss that the 0-5 had his rank on backwards. The goal was to advise him without embarrassment.
Leaders need to be open to, at the right place and time, disagreements from their juniors. I would establish a free exchange zone (my office at morning meeting) where they could tell be what they felt they needed to tell me. I had the best Department in LARGE part due to great comms between my people and their chain-of-command, ending with me.

If possible, I would look for the same rank female in my platoon, ask her the same question you were asked on regulation and without pointing show her the SSGT
And ask if she is in regulation.
Then hopefully someone wil confront her.
At least that's what I would do.

Wear i agree with all of the answers I have seen so far, you really need to choose your battles. Using the chair of command, is always the safe answer. In this case, with a visiting General, I can guarantee there will be plenty of senior NCO's around, kissing stars, and ensuring order. Find one (preferably a female), give a nudge, point in the right direction. I guarantee said SSG will be pulled aside and corrected and the black lipstick will be removed. None of them want the General to see a jacked up NCO in their command.

Be tactful and even if they don't treat themselves appropriate to their own rank doesn't mean you should do the same. Treat them according to the rank. I've corrected a Major General and got a coin for when I was a PFC is name and army tape were on opposite. It's a matter of letting them know nicely if they continue to do it report them to the next higher up the chain or if they get in your face over it. I hated piss poor appearance in my Platoon it wasn't tolerated.

Hell at Ft. Bragg when I was there if you didn't tactfully correct someone even of superior rank with general power of authority and the Post Commander saw it he'd have both of your behinds. His biggest pet peeve was LTs walking and talking on cell phones and even a PVT was expected to make a tactful correction.

Byron Skiinner. Unless you are a member of an organization such as Military Police or working for a commander who has specifically assigned you with the task of making sure female enlisted personal meet specific grooming protocol, let it be. If there is an issue Im sure a two star will notice and detail somebody to correct it, or as in most cases really doesn’t give a shit anyway. Also even though you didn’t mention race, I would just guess that race is a factor here

That would be up to the person and who they were confronting. Most people who have rank above yours, depending on disposition, may not listen to you. And then if you go to a superior, they may label you a trouble maker. It is up to someone over that person to make the corrections and if they aren't available to make the correction, and expect everyone to do their work, sometimes it can be a no win situation. I was in Okinawa in 1984 and we were do a field test on putting up a Hospital for operation in 72 hours. A storm came up and I got hit by lightning. I had to walk to the dispensary to be evaluated. I ended up with post concussion syndrome, but then I walked back because the Marines had their ambulances and trucks lined up. The inspection started and the commandant of the Marine Corps PX Kelly looked at me and said I looked like hell. My Lt. told him I got hit by lightning, he said, "Jesus Christ son, are you ok?" I said I had a headache and told him about the area I was covering. Every physician that I worked with appreciated my work. I got a commendation for my work on this field exercise as I was being tested for advancement in rank. Most of the officers in the battalion liked that I was teaching the other corpsmen. One officer, I didn't have much respect for because he tried to make everyone's time on Okinawa under him, miserable.

As the Sergeant Major said; "Absolutely, just use tact."
Also, have your own ducks in a row before you call her out on it. Not just you not wearing out-of-Reg make-up, but across the board. Never correct someone if your shit is not squared away.
It also does not hurt to know exactly which part of the Reg is being violated, as in Reg#, page, chapter, section, paragraph, etc. because an NCO that is willing to flaunt the Regs is more than likely going to argue about you calling them out on it.