Medieval white Eurocentricity aside, the faires and fests are for everyone. Please dress as nobility! Look regal as fuck while you do it.

If you're worried for any reason at all (or just because the rest of the world existed during the era, was full of color and life, and the Euro stuff can sometimes get a little stale) dress as non-European styled royalty. It's a fun way to express admiration for lots of cultures and times so long as it's done with good intention and respect for currently extant peoples.

I've been going to my local faire growing up my whole life and people having a good time has always trumped assholes trying to call someone out. That gets shut down pretty fast.