I didn’t know how to respond when my boyfriend said I am beautiful “for a black girl.” How would you respond?

My boyfriend said I’m beautiful “for a black girl.” I can’t seem to get it off my mind. I didn’t even know how to respond. I’m still reeling over it. I can’t tell if he means that black women are not beautiful or that I’m not beautiful or just how to respond to him. I’m socially awkward.