Dye, substance used to impart color to textiles, paper, leather, and other materials such that the coloring is not readily altered by washing, heat, light, or other factors to which the material is likely to be exposed. Learn more about the properties, uses, and development of dyes in this article.Dye - Colorants, Pigments, Textiles: In dyeing operations, the dye must become closely and evenly associated with a specific material to give level (even) colouring with some measure of resistance to moisture, heat, and light—i.e., fastness.