Agent for coloring fibers and method for temporarily coloring fibers

A composition for coloring fibers (A), which is prepared by mixing two components (A1) and (A2), wherein component (A1) has an acidic pH and contains at least enamine of Formula (I) or its acid addition salt of Formula (Ia),

• wherein R1 represents a single ring or multi-ring aromatic group, an unsubstituted 5-membered or 6-membered heterocyclic group, a 5-membered or 6-membered aryl group, substituted with a C1 to C4 alkyl group, a C1 to C4 hydroxyalkyl group, a hydroxy group, a methoxy group, a dialkylamino group or a halogen group, or a 5-membered or 6-membered heterocyclic group, substituted with a C1 to C4 alkyl group, a C1 to C4 hydroxyalkyl group, a hydroxy group, a methoxy group, a dialkylamino group or a halogen group, R2 is a linear or branched C1 to C8 alkyl group or a linear or branched C1 to C8 hydroxyalkyl group, a C1 to C8 alkoxyalkyl group, wherein oxygen atoms may be located between the carbon atoms of the alkyl chain, R3 is a linear or branched C1 to C8 alkyl group, a C1 to C8 alkoxyalkyl group, a linear or branched C1 to C8 alkylene group, a C1 to C8 alkoxyalkylene group, an oxygen atom, a sulfur atom, an —NH group, or an —NR group, wherein R is an alkyl group, an alkoxyalkyl group, a hydroxyalkyl group or hydrogen, the R1 and R3 groups, together with the nitrogen atom and the carbon atom of the basic enamine structure being able to form a cyclic compound and R4 being hydrogen, a linear C1 to C4 alkyl group or a branched C1 to C4 alkyl group, A− being the anion of an organic or inorganic acid, and the component (A2) having an alkaline pH and containing at least one Schiff's base of Formula (II)
• R7HC═NR8 (II)
• wherein R7 is a group of the following formulas
• wherein Y and Z in each case are an oxygen atom, a sulfur atom or an NRa group, R1′, R2′, R3′, R4′, R5′, R6′ and R7′ independently of one another are a hydrogen atom, a hydroxyl group, a methoxy group, an aryl group, a halogen atom, a —CHO group, a —CORa group, a —CO2Ra group, an —NO2 group, an —OCORa group, an —OCH2 aryl group, an —NH2 group, an —NH3+ group, an —NHRa group, an —NRaH2+ group, an —N(Ra)2 group, an —N(Ra)3+ group, an —NHCORa group, an —NHCOORa group, in which Ra represents a hydrogen atom, a linear or branched C1 to C4 alkyl group, an optionally substituted aromatic carbon ring or heterocyclic ring, with the proviso that at least one of the R1′ to R7′ groups is not hydrogen, and R8 is a group of the following formulas
• wherein R1″, R2″, R3″, R4″, R5″, R6″ and R7″ independently of one another are a hydrogen atom, a methyl group, a halogen atom, a hydroxy group, a C1 to C4 hydroxyalkyl group, a benzyl group, an optionally substituted aromatic carbon ring or heterocyclic ring, a methoxy group, an ethoxy group, a carboxy group, an —NH2 group, an —NHRb group, an —N(Rb)2 group, in which Rb is a hydrogen atom, a linear or branched C1 to C4 alkyl group, a C1 to C4 hydroxyalkyl group, an optionally substituted aromatic carbon ring or an optionally substituted aromatic heterocyclic ring and R8″ is a group, required to form a natural α-amino acid.