Please consult a dermatologist. There is some remedy for such a problem. Basically, you can be provided with medication that can increase or decrease the melanin which dictates skin color.
By increasing the melanin, your brother can be made darker (more likely his own skin tone) or like Michael Jackson who is suspected of having the same affliction, you can eliminate the production of melanin, creating that pale white tone.
You do not need surgery if you brother has developed this recently as it can be rectified swiftly.
Please seek medical advice as there are several options available for vitiligo.
Michael Jackson used a cream called Benoquin (which is now not available as the manufacturer has stopped making it) to depigment, it's v.dangerous as it can lead ppl to develop skin cancer (as he is also suspected of having). Users of it were meant to very very careful in the sun cos their skin becomes sensitive cos of their lack of melanin, they have to always use sunblock (no matter how sunny or not the day is), are not meant to allow their skin to be exposed to sunlight, must use umbrellas etc. which is nearly impossible. That drug was also only really recommended for ppl who had vitiligo on 50% or more of their body. Like u mentioned the person wouldn't merely turn 'normal' white, it's super pale, almost a 'goth' type white skin shade.