Michael Jackson's skin color changed by a disease known as "Vitaligo". Vitaligo causes the loss of skin color in blotches. It can effect skin on any part of your body. It can also effect hair and inside the mouth. That explains a little bit why Michael Jackson went from his original brown skin color, slowly transforming to a lighter skin color.
He had a skin condition called vitiligo. Which is white patches all over the body. It's very common in all races. He chose to bleach his skin (white) to match these patches. Although there is a topical medicine that can be prescribed to help this.
