I bought this male should I go back and get the other?

Thanks everyone! I wish they were a pair but they're both males :(.

That's the thing about YBs. Some may look like they MIGHT be, but aren't, but when they ARE it's easy to see. You've got yourself a yellowbelly.

First one definitely yellowbelly, and really looks like a pretty good example of one!

Second one.. I'm less sure on.