The fact that you're conscious of these biases and are trying to take a thoughtful approach to avoiding them probably means you don't need to worry too much about it. I think it's probably unrealistic to be able to memorize and identify every media star, and getting some actors of a certain ethnicity confused doesn't automatically make you racist. I mix people up all the time, regardless of their background, so don't sweat it too much. Over time, your recognition will improve, as with any other activity. Good luck!
Yeah but these people always think that they're the exception to the rule