Bathochromic and hyperchromic absorption of p-nitrophenylhydrazones in alkaline dimethylformamide (DMF), that was shown in the colorimetric procedures for some steroids, was studied using several model compounds in various solvents. The color was ascribed mainly to the formation of quinoidal anion (I). The solvent effects of DMF as a dipolar aprotic solvent was discussed from the point of view of the cationic solvation and the increase in activities of hydroxide anion added as well as carbanion (I) formed was regarded as responsible for the hyperchromic absorption. The bathochromic effect of DMF was explained to be shown as a probable result of shielding the anion (I) from the cationic field by the solute-solvent interaction.