The belief in racial equality is faith-based to begin with and is not grounded in facts, evidence, or logic. Therefore, no amount of facts or proof would be enough to sway these true believers.
Just as proof of God's nonexistence would be met with claims that God fabricated such evidence to fool people, proof of negro inferiority is always met with claims that an omnipotent, omnipresent, omniscient white entity is somehow manipulating the evidence to test the faith of egalitarians.
Evidence which proves that races are inherently different already exists by the boatload, but historically speaking it takes a long time for religious beliefs to yield to facts. The Catholic Church didn't officially admit that Galileo was right until 350 years after his death. I expect it to take at least that long for egalitarianism to reach maturity and admit at least some of its mistakes.