You can also find siblings of which one could pass as black and the other as white. Sometimes even parents and children. Would they then be of a different race?
What are the different human races you can identify from appearance if I may ask?
So you might identify somebody 90% European as 100%, and your point is what exactly?
My point is that race is a very loose definition which quickly falls apart in practice, and thus it's just plain stupid to use it to decide whether people should be admitted to college or not.
In calling it a loose definition, you’re disputing your own premise behind your comment about two siblings being able to “pass” as different races.