Just gonna post a laundry list of evidence:

>Reconstruction
the real chimpouts started when there were black-white female couples forming during reconstruction. Of course, before this, white slavemasters often fucked their female slaves far more often. But despite this fact, whites were still extremely offended by even a few examples of the reverse pairing.

>Aryan caste system
Light brown Indo-Aryans conquered medium brown Indus valley people in 4000 BC.
However, an unmentioned fact is that mixing in Northern India was not frowned upon for the first several hundred years.

It was only after this period of mixing that the caste system was created, based on skin color.

In other words, the caste system was created to deal with the problem of darker men (either Indus inhabitants, or even darker Dravidians from further south) taking lighter wives.

>Black men are taller
In a study using NFL quarterbacks, Whites perceived those with Black faces to be taller and stronger than those with white faces, even though their actual heights were equal. The "height bonus due to dark skin" was 1 inch.

>Middle Eastern features get the womb
A Czech study on White Czechs sorted men into blue-eyed vs. brown-eyed pools. They tested women on their sexual preferences of each color male.

While not ovulating, Czech women preferred the blue-eyed Czech men.
While ovulating however, and at their most fertile, Czech women preferred the dark eyed Czech men. Facial averages posted.

>other mammals
Lionesses prefer male lions with darker manes
The only known bear hybrids are between Grizzly male and Polar bear females