I work in a 'cool & funky' industry and office. More so than architecture is say, though close.
We do have problems quite regularly with young grads or admin staff who can't see the difference between what they're wearing / hair/ general turn out and what other people are wearing. It's so tricky particularly when people feel they somehow have a right to wear exactly what they want, when in a honesty, they kind of don't, and the informality can trick people into thinking there are no rules vs different rules.
I'm thinking of the young woman who turned up to a client meeting with no bra, strappy top so thin not only were there nipples pinging out you could clearly see the aerola. Oh and flip flops. We didn't get the project plus the client complained. I think hr addressed it as 'office wear is not beach wear' to avoid the hideous cringing of personal body parts!
And then there was the young man who stank, linen shirts became slept in crushed wet rags, and to top it off he wandered around with no shoes on (& very hairy toes & feet apparently - it was then we found out someone had a phobia of hairy toes - who knew?!), and put his feet up on the table as well.
Both examples were clearly not professional, but they had no idea and were so upset at someone having 'the talk'. The appearance problems were also a sign of not really 'getting' what was required of them professionally, and just not understanding that any office attire is about expressing the companies values.
There exists anywhere an office culture and it's rubbish but people get on better if they know how to play it.
Now I've been putting this bit off but will say it anyway even though I disagree wholeheartedly, as maybe it's relevant to your situation. Utterly and totally unfair, but I have noticed that not all dress codes are made equal. Often senior staff and/or profit making staff are given more licence over things like appearance, punctuality etc. Bottom line is if you contribute directly to the bottom line, you have more power in a company.
I've noticed that admin staff, finance, and hr all seem to dress that notch more formally. Don't know whether that's because their professions are more formal/ traditional, or because they find they are t taken as seriously, or are simply expected to be better turned out.
I also have noticed that more senior employees get to have their quirks and personal style that bit more. I know this can be a problem as when someone right at the start of their career joins, and gets pulled up on something, they might say/ think 'hey that's cinpletely unfair, so and so does X so why can't i?' .... One of the really unfair bits of working life! Trouble is, if so and so brings in 1M a year, then their performance means little issues tend to get overlooked.
Also that same person might be looking shabby / a bit ripe as they've pulled an all nighter or just come of a long haul flight, often both. So, then the junior thinks, oh great no one cares what people look like, when they just don't have the full facts to judge what's happening...
Anyway, that's all I can think of to share that might be helpful :)