Right, I'm bored, so last one.
It's a long established etiquette not to wear white to someone else's wedding. I'm sorry you don't like that (and honest to God don't know how you missed it, truly) but that doesn't mean I and OP and other posters made it up. It's a thing. A longstanding thing. Don't blame me. If I was going to make up stuff to spread around, I wouldn't choose this. I'd make up something like it being the height of rudeness not to consider plain, boring middle aged women like me not to be the height of sexiness and glamour. Or something.
You didn't know, ok. Now you do, you have a choice. Wear something from the almost infinite number of hues that you know for sure is appropriate and definitely won't cause offence or upset, or make a fucking point of choosing something from the one colour shade that you now know might do. And now that you do know, you would be making that point.
You probably won't ever know if you did cause upset because brides and guests tend to be polite (like I said, nobody was rude or hostile to the women who wore white at those weddings). But that doesn't mean you didn't. And if you do deliberately make the one choice that you know might cause upset rather than the zillions that you know won't, that's kind of the definition of rudeness.
I appreciate that it sucks to realise you may have made a mistake in the past, but if your response to that is to dig your heels in rather than just do something different from now on... it's not the bride's failing if you do offend her.
Just wear another colour. It's possibly the least draconian rule there is, other than getting off with the groom during the reception. Don't do that either. And just don't wear white.
Have a great Sunday.