Many cultures recognize white magic as the good, healing sort of magic, while black magic is the darker sort. In voodoo, there is no distinction between white and black. Instead, when an evil spirit is conjured or bribed by an evil person to do something bad, it’s called red magic. The color of the spirit is red, and when a practitioner allows an evil loa to take possession of them, their eyes turn red, showing that evil is present.
Sometimes a benevolent spirit can turn evil by the wishes that are imposed on it. This is in complete contradiction to the actual teachings of voodoo, which center around the good and the charitable. Part of the role of a female practitioner (a Queen) and a male practitioner (a Doctor) is to stop red magic before it happens.