because there is something called biases
a person might unconsciously or consciously believe that people of color are more likely to commit crime or be dangerous. that’s a bias. a different person might unconsciously or consciously believe that people of color are all naturally good musicians. that's also a bias.
negative biases are what gave birth to what we today consider white privilege.
but biases, negative or positive, exists everywhere and in everyone, and it can be against anyone from anywhere.
if there's someone that you find extremely attractive in front of you asking you a question, you'd most likely not act your absolute self, right? in that case, the person asking a question wouldn't be treated, by that person, like any other random person.
it doesn't need to be a bad thing. i included the word generally because not all people will give the same treatment to everyone, and it doesn't need to be related to race at all