DYEING COMPOSITIONS FOR KERATINOUS FIBRES CONTAINING AT LEAST ONE CO-SOLUBILISED N-SUBSTITUTED 2-NITRO-PARA- PHENYLENEDIAMINE + PROCESSES FOR DYEING KERATINOUS FIBRES

摘要

The invention relates to a dyeing composition for keratinous fibres containing, in a suitable vehicle, at least one 2-nitro-para-phenylenediamine direct dye, in free or salified form and also at least one xanthine derivative of formula (II) (II) where n=0 or 1, R'3=H, R'1, R'2, R'4 and R'5 are substituents having various significances, the said compound of formula (II) being in free or salified form. They can be used for dyeing hair.