It's not about skin colour per-say. It's about racial stereotypes.
White men are more attractive in dating IRL because they have a perfect combination of being seen as masculine, and successful, and therefore also do well in porn. Black people are over-represented in porn because of the image of hyper-masculinity, and low-class danger that is sought after in porn but not real life (thuggishness), and asian men are under-represented because of the image of femininity, despite being more successful on average.
If any of these stereotypes changed, so would the porn market change to fit the stereotype. In the meanwhile, stop getting hung up on race, and if you cannot, then remember that things that are positive in porn are often negative in real life and vice-versa. Porn is all about being taboo.