The SOLVENT DYES are the dyes that dissolve in organic solvents. They are often employed in the form of a solution in an organic solvent. Organic solvents, hydrocarbon fuels, waxes, lubricants, polymers, and other nonpolar hydrocarbon-based products are coloured with solvent dyes. Solvent dyes are used in a variety of applications, including fuel dyes. Their molecules are normally nonpolar or very slightly polar, and they do not ionise. They are not water soluble. In solvents, they create a colloidal solution. Solvent dyes are used to imitate gold as well as other transparent metallic effects on metallized polyester films.