They have no rules. Look at Snow White in the remake. They don't even use makeup or CGI to make her "skin white as snow" and "fairest in the land".

Domino was turned from snow-white into black, and they even ritually sacrificed a black woman's life (black lives don't matter - Disney) for it to not even have a white stuntswoman or even as much as have her wear a helmet (which too could be super easily fixed by the CGI, but she just had to be killed).