I like the idea of there being regalia, and think it's likely there would be. I would have to agree with niniane's assessment, certainly with respect to the jewelled regalia. If it already existed, as a treasured relic handed down over the ages, it would be a prime target for theft, that's for sure, but I don' think they'd be creating any at this point. And this has just given me an idea, so thank you for asking!

However, there could be special robes, made with rarer fabrics and colors poorer people couldn't afford? I did a bit of research in that regard recently. It's a thought, if you're looking for something that's still plausible and yet not extravagantly expensive.