They should dress in good taste. Anyone who doesn’t know what “good taste” means probably would not be able to carry out the requirements of the office, sorry to say. It probably shouldn’t be distinctive clothing, it should just be something that someone who can do other business or social tasks such as going to a decent restaurant, serving on jury duty, or holding down a job in a professional looking office would wear in those settings. Nothing particularly complicated here.
The big beef I have is long hair, and my hair is very long, by the way, so I have no prejudice against the long-haired of either gender. But long hair has its own handling issues, and if you haven’t figured those out, you have no business distributing communion. I should say that the big beef I have is long, unsecured hair, meaning a big strand of the extraordinary minister’s long hair went dangling into the chalice or the ciborium. Yep, actually saw this happen, right in my communion line, right into the Most Precious Blood! You could have knocked me over with a feather. When she offered me the chalice, I said, “Amen,” and then hissed, “Hair!” I don’t know if she got the hint.
I don’t know what the correct procedure is for handling something like that, but I sure called the parish office and complained about it to the priest on Monday morning. It has to be some kind of sacramental abuse, in addition to the issue of a communicant having to drink contaminated consecrated wine. Father was as appalled as I was, knew who the young lady was, and said he’d talk to her about it.
Long-hairs, of either gender, at least have the good sense to tie it back or put it up! Yikes!