A novel colorant compound is provided which is the addition product of an organic chromophore having at least one reactive hydroxyl or amine substituent, a polyisocyanate, and a carboxylic acid, sulfonic acid, or salt of either thereof. The polyisocyanate, added in a molar excess relative to the number of such reactive substituents, reacts with the reactive hydroxyl or amine groups to provide terminal isocyanate groups. Subsequently, the carboxylic acid or salt thereof, also added in an amount excessive in relation to the number of terminal isocyanate groups, reacts therewith to from urethane moieties on the colorant. Such a compound provides excellent ink compositions upon dilution and are very soluble within all the standard ink diluents. Furthermore, such colorants provide good jettability, waterfastness, washfastness, and the like, within ink-jet applications on various types of printing substrates. A method for producing such a colorant and specifically printed substrates colored therewith is also provided.