That's because Jamaica is a resort type area. It's also not true of the philippines, well..if you count whities as the minority. But that's because pretty much everyone be po there. The mountain people are both poor and minority though in that particular case.
Also Misty's family was just generic white that had been there for a while, maybe their former home was destroyed and that's why they live there?
Baa baa black sheep have you any booze? No sir, no sir, I'm a....sheep~