1,3-Dihydroxybenzene derivatives and colorants containing said compounds
1,3-Dihydroxybenzene derivatives of general formula (I) or (Ia) or physiologically tolerated, water-soluble thereof wherein R′1 denotes substituted pyridyl group, a pyrimidyl group, a group of formula (IIa) or (IIIa) and the dyeing agents for keratin fibers containing these compounds.