A class of dyestuffs that are applied directly to the substrate in a neutral or alkaline bath. They produce full shades on cotton and linen without mordanting and can also be applied to rayon, silk, and wool. Direct dyes give bright shades but exhibit poor washfastness. Various aftertreatments are used to improve the washfastness of direct dyes, and such dyes are referred to as "aftertreated direct colors."