The autopsy proved that he had vitiligo.I don't subscribe to the idea that he has vitiligo at all.
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Michael Jackson’s Autopsy Revealed Numerous Surgical Scars; Confirmed Vitiligo
Michael Jackson had always insisted that he suffered from vitiligo, a skin condition which causes patches of lost pigmentation. But it wasn’t until after his death that an autopsy confirmed the truth behind his unusual skin color
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He changed it because he hated his dad Joe, not to be White.He also changed his whole face to mimic white features. And his kids aren't even biologically his. I think he has severe racial identity issues.
He said "I'm a black American, I am proud of my race. I am proud of who I am. I have a lot of pride and dignity." - Michael Jackson
Michael Jackson was staunchly pro-Black and never once ran away from it.