The description given by the OP is not clear. Does it mean their porn careers or their private lives? Nevertheless, I can't say anything for Onlyfans/Manyvids girls, given their infinite and indefinite number, but even if they confirm 'dating' only black men in their private lives (many claim so), mainstream porn stars will fuck any race on screen. An exception might be Riley Reign who had told that he wants to fuck only black guys in her porn career, but she has fucked white guys nonetheless. In any event, the porn world has no clear distinction between gimmick and truth.