In Lil' Kim's, Beyonce's or Niki Minaj's case the vast majority of the buyers of hip hop music are suburban white teens and twenty somethings. To stay relevant you have to appeal to their demographic..Even if it means lightening your skin and changing hair color.
Lil Kim had said that all the dudes she had dated or liked, liked light skinned women. She had her hearted broken when Biggie married Faith Evans. And that's when the mental breakdown of the low self esteem having Lil Kim started. After Biggie died, came the weight gain, and theme the breast implants, and the starting to turn herself into a version of Faith Evans. Next it was being friends with spam Anderson (guest starring in Anderson's VIP show) and then the blonde hair started to show up. Next up was the massive plastic surgery and skin bleaching. Turning herself into something looking Asian or Latina.
Niki Minaj, another New Yorker, was skinny, grew up in a home with a lot of fighting, sad that she often came up with various stories of an alternate life. She got a ton of work done, especially her backside and breasts, and wears tons of colorful wigs. She made a name for herself as being either a lesbian or bi, and then went full tilt into vamp female rapper, which is the same as Lil Kim.
Notice how both her and Lil Kim (as well as Foxxy Brown) come from NYC, both are brown skinned females, both only seem to only play on their sexuality, both have talked about self esteem issues, both have gotten major work done.
And Lupita is fine.