The present disclosure relates to compositions and methods for improving the quality and durability of color in artificially colored hair. The methods employ salts of hydroxy-polycarboxylic acids. The salts of the hydroxy-polycarboxylic acids are incorporated into a pre-color treatment composition (a composition applied to the hair prior to coloring the hair) or added directly to the coloring composition (in-color treatment composition). The salts add alkalinity to the coloring process. Hydroxy-polycarboxylic acids are incorporated into a post-color treatment composition (a composition applied to the hair after coloring the hair). The salts and the acids act as chelators, fixing the dye molecules to the hair, thereby imparting color fading resistance to the hair.
