What would be considered offensive wear?
I have concerns that when we spend our time attempting to police the potential impact of the possibility of the perception that someone might conceivably be lead to recall a reference to another source that in some subset of certain populations may generate sensations, thoughts, or feelings of disquietude, perhaps we are treading well outside our area of expertise.
Let me draw an example: deck checks. If I were to check decks at any event–any event–I could find variations on the sleeves (or lack thereof) in every match. I suspect you could, too. How many times have you worked with judges and seen them stamping a deck on a table to line cards up, turning their heads sideways, and them leaning close in so they can look at the sleeves? This is what I call the “too much science” technique. I often see it with inexperienced judges, and it's an immediate sign of failure. If you see a player turning his head sideways and leaning in to draw a card, please just DQ the guy; don't take up time in a deck check trying to micro-analyze his deck. (Or DQ the person; don't waste time on their deck, if you prefer gender neutral wording.)
In any given deck, if you look hard enough, you will find discrepancies in functionally any deck. The job of judges isn't to put sleeves under a microscope; it's to provide reasonable levels of play. And yes, we leave ourselves the option to take additional action if ever a player expresses a concern about a player's sleeves.
I chose “expresses” very intentionally. Players may express in many ways. Verbally to a judge is most common to us. Verbally to friends is also (if not more) common. Body language, tone during other verbalization, and other expression pathways also could apply. We don't judge in a vacuum, and maintaining awareness of the non-verbal expressions around us helps us be better at what we do.
With sleeves, sometimes we know right away it's bad, sometimes it's worth a chat and change, sometimes it takes a player's expressing concern, and sometimes they are acceptable. Acceptable does not have to mean perfect in all ways, just within reasonable expectations.
I believe the best approach to clothing is similar.
If your impulse seeing a shirt is, “that's not ok,” then act right away. This may involve asking the TO to look into it rather than you taking action with the player. Generally, I recommend all clothing issues be handled via the TO as it is also their reputation at hand.
If your impulse is, “that's pretty sketchy,” consult with the TO or another judge and act if needed. Again, the TO perspective often helps here.
If your impulse is, “why would I pay no mind to women and seek to advance my pecuniary status?” then perhaps it's time to pay attention to how the players behave and react to see if they show expressions of discomfort.
Even if your impulse is “I love that shirt,” be open to discussion with people that may have their own concerns.
I have found that being welcoming of player feedback and giving player concerns real attention goes much more positively in the long term than any given shirt. If your players know or see that you are engaged in their enjoyment, they'll express more to you. And when players are happy and playing without concern, sometimes the right course is to be vigilant without being vigilante.
Ultimately, it is on you as the judge in your local event to understand your TO's perspective, know your players, learn what works or doesn't for them, and to set reasonable standards that balance self-expression and acceptable attitudes. As we go to larger events or other regions, talk with the seasoned judges about that area's or that TO's expectations. Seasoned judges can often help you get up to speed at unfamiliar events. There's not one answer to fit every case. Unlike some shirts, one size does not fit all.