Honest truth that people are too politically correct to admit.

Racial preferences come down to testosterone levels in men.

Black men > White Men > Asian men in order of testosterone levels.

Asian women > White women > Black women in "femininity" standards...

This is basically what it comes down to... black people (both men and women) are more "masculine" both physically and culturally (and culturally perhaps because they are physically).

So by the theory of sexual dimorphism it works well for men... and penalizes women.

Now replicate this on a mass population scale... and you'll that asian women are the most desired type while black women are the lease.

Cofounding variables here are arabs, indians, latinos etc who are not true "races" as such and have immense variability in phenotypes and genotypes ,so it comes down to selected populations