Dye compositions, especially for human hair containing the new chemical compounds of the general formula ##STR1## in which formula the radical Z is selected in the group formed by the hydroxyalkyl, alkoxyalkyl, acylaminoalkyl, carbalkoxyaminoalkyl, mesylaminoalkyl, ureidoalkyl, aminoalkyl, monoalkylaminoalkyl, dialkyl-aminoalkyl radicals, and the salts of the corresponding acids. Among the preferred acid salts, the sulfates, hydrochlorides, phosphates and tartrates may be mentioned.This dye is particularly suited for use with a coupler of the formula ##STR2## in which formula R.sub.3 and R.sub.4 are identical or different and may represent a hydrogen atom, alkoxy radical, or an alkyl radical and in which R.sub.5 is a radical selected in the group formed by the acyl, carbalkoxy and ureido radicals.