I think people are attracted to what they find attractive and you would be overstepping yourself to dictate to them what that can or can't be.

Frankly I find the idea that you would try to externally put rules around that not much different than the people who would tell trans people that they should follow their rules about sex and gender.

So if you would disapprove of a white person who only found other white people attractive (or literally any other combination there), I would tell you that their story isn't yours to tell, their body and feelings aren't yours to control.

I don't have any particular opinion on white people only attracted to white people except that it isn't my business. And I would happily protect them from you if you thought it was your business. Because it wouldn't be. So long as all parties are able to consent I'd tell your to mind your own business.

The exact same thing I would say about trans people. And gay people. And asexual people. And all people.