What is a "diversity hire"? Anyone that's a minority? Or perhaps someone that _you_ believe wouldn't have been hired if they weren't a minority? Let's give you the benefit of the doubt and say it's the latter.

How would you know if a colleague of yours is a "diversity hire" without making assumptions? How do you know that you're just not as good? Because you don't think their work is high quality? Maybe you're a bad judge because your work isn't high quality. Or maybe you only see part of their work? Or maybe your pre-judgement has already doomed you to biased analysis of anything they do.

Or maybe if you're worrying about this you're just not very good.