(Irregular plural: bleaches).
1. The act of whitening something by bleaching it (exposing it to sunlight or using a chemical bleaching agent).
2. The whiteness that results from removing the color from something.

Decolorization of colored materials. The two main types of bleaching agent are the oxidizing bleaches, which bring about the oxidation of pigments and include the ultraviolet rays in sunshine, hydrogen peroxide, and chlorine in household bleaches, and the reducing bleaches, which bring about reduction and include sulfur dioxide.
Bleaching processes have been known from antiquity, mainly those acting through sunlight. Both natural and synthetic pigments usually possess highly complex molecules, the color property often being due only to a part of the molecule. Bleaches usually attack only that small part, yielding another substance similar in chemical structure but colorless.

Changing to a lighter color; SYN. lightening.