They want a paler skin tone, just as people who tan want a darker skin tone. I have no idea whether they want to look white (whatever you mean by that), but I doubt it just as I would doubt that someone who tans wants to look black (whatever that means). They are most likely to be looking for a different gradation of skin tone.
I try to avoid judging people on what they choose to do to their bodies. IMO there’s nothing right or wrong about what Mel B has done to her skin (assuming she has done anything). I certainly wouldn’t lecture her on her choice.