Abstract: Composition for the oxidative dyeing of hair based on a combination of developer substances and coupler substances contains, as developer substance, a diaminopyrazol of the general formula (I), ##STR1## wherein R.sup.1, R.sup.2 and R.sup.4 are identical or different and designate hydrogen, alkyl with 1 to 4 carbon atoms, hydroxyalkyl with 2 to 4 carbon atoms, benzyl or phenyl, and R.sup.3 is hydrogen, alkyl with 1 to 4 carbon atoms, hydroxyalkyl with 2 to 4 carbon atoms, with the proviso that the amino groups are in 3,4 or 4,5 position, or its physiologically tolerated, water-soluble salt, new diaminopyrazol derivatives of the above general formula I are also described herein in which R.sup.1 is methyl or benzyl and the R.sup.2 and R.sup.4 are either benzyl, phenyl, hydrogen, alkyl with 1 to 4 carbon atoms or hydroxyalkyl with 2 to 4 carbon atoms and R.sup.3 is either hydrogen, alkyl with 1 to 4 carbon atoms or hydroxylakyl with 2 to 4 carbon atoms.