Hair dyeing composition

A hair dyeing composition, comprising a first part comprising a component (a) and a second part comprising a component (b), wherein a pH upon use is 7.5 to 12:

• (a) a nitrogen-containing compound expressed by the following general formula (1) or a salt thereof:
• wherein n denotes an integer of 1 or 2,
• each of R1 and R3 to R5 independently represents a hydrogen atom, a hydroxy group, or an alkyl group, an alkenyl group, an alkynyl group, a cyclic hydrocarbon group, an aralkyl group or a cyanated alkyl group each having 12 or less carbon atoms, or a 5 to 7 membered-ring saturated or unsaturated heterocyclic group,
• two of R2 may be the same or different, and each represents a hydroxy group, —R or —OR, wherein R represents an alkyl group, an alkenyl group, an alkynyl group, a cyclic hydrocarbon group, an aralkyl group or a cyanated alkyl group each having 12 or less carbon atoms, or a 5 to 7 membered-ring saturated or unsaturated heterocyclic group,
• wherein R1 to R5 may further have one or more substituents selected from the group consisting of a hydroxy group, an amino group, an alkyl group, a cyclic hydrocarbon group, an aralkyl group, a heteroaryl group, an alkoxy group, an ester group, and a cyanated alkyl group each having 8 or less carbon atoms,
• and wherein two or more of R1 to R5 may be taken together to form a saturated or unsaturated 3 to 8 membered-ring, and the ring may have a substituent selected from the group consisting of a hydroxy group, and an alkyl group and a cyclic hydrocarbon group which have 12 or less carbon atoms and optionally may have a substituent;
• and
• (b) an oxidizing agent.