This is totally normal and his reaction is one of typical racism-phobia. This exist heavily within black people and within the global mindset. I'm not trying to dismiss their feelings about this as irrational btw. They are enforced in thinking this way through the media and other social relations. When you say something bad about black people, to them it feels like you are insulting them too.

Just switch black with something else and how would he react. "I don't date spanish/italian women. They always seemed very warm-blooded and emotional to me. I don't know but this just never appealed to me. I prefer women like here in norway that are more laid back."

Would he still big deal call you a racist here?