This invention relates to unsubstituted and polymeric leuco colorants for use as consumer product additives to indicate a product function by color change, to make attractive or distinctive visual effects, or to provide latent or delayed color generation. The colorants may be present in a stable, colorless state and may be transformed to an intense colored state upon exposure to certain physical or chemical changes. Alternatively, the colorants may be transformed from one color to another color upon exposure to certain physical or chemical changes. The colored form of the unsubstituted or polymeric leuco colorant may be transient, since the colorant can revert back to its colorless form or its original color after the physical or chemical activation has been removed or changed. Polymeric leuco colorants are typically comprised of at least two components: at least one leuco chromophore component and at least one polymeric component.