There are any measurable physical, biological differences between races. Black people have dark skin & frizzy hair. Caucasians don't. Asians (99% of them) have slanted oblique small single-eyelids eyes, flat nose, yellow skin while Caucasians have folding eyelids, big eyes, big nose, white skin. Clearly measurable.
Most importantly, apparently, racism isn't defined as racial hatred but as racial superiority. That strengthens my points. Racism is not even hating a certain race, ethnicity, country but about the superiority of a race, ethnicity, country. Hence, hating (or being repulsed) a certain race, ethnicity, country because of an attribute (like face or it having done something wrong to you) is not racism aside from being rightful anyway. Even on the matter of superiority, it is within the individual rights & it is rightful (legitimate) to distinguish what you like & what you don't like "without declaring" superiority. It is an individual right morally, rightfully, legally.