I want at least one purple fish for my aquarium, I'm trying to think of some. There was one in particular I had in mind but now I can't think of the name. Purple tangs possibly? I normally only see yellow tangs so I was really attracted by this one.

But any purple colored fish are welcome, not just tangs, if people want to suggest me some!

And I was also wondering if these tangs would thrive in the average saltwater aquarium, like yellow tangs do?

Yes, you're thinking of purple tangs https://www.liveaquaria.com/product/372/?pcatid=372 Pretty common in the hobby and not difficult to care for either. They're a great tang - I'd heartily recommend them!