In light, black is the absence of colour. In pigment, it’s all colours mixed together. Either way black represents space, the infinite, never-ending, all-encompassing. It is dark and mysterious, and symbolizes mourning and evil in Western cultures. In clothing, an all-black outfit can be goth or elegant, depending on styling. Black is the easiest neutral to work with because it goes with absolutely everything. It is safe, and no-fault, while simultaneously evoking power and sophistication.
White symbolizes purity, innocence, and cleanliness. It is the opposite of black: in light it is all colours, in pigment it is none. White is a blank slate, an empty canvas. While black is the colour of death and mourning in western culture, in other cultures white fills this role, due to the idea of death being the beginning of a new life, of renewal.