| abstract |
Natural-acting oxidation colourings of keratin fibres in the brown-black range are achieved using indolines of formula (I) as primary oxidation dyes, wherein R1, R2, R3, R4 and R5 independently of each other represent hydrogen or alkyl groups with 1-4 C atoms, or R4 and R5 together with the oxygen atoms to which they are bound represent an alkylene dioxy group with 1-4 C atoms, or the salts thereof produced by oxidation with atmospheric oxygen without using additional oxidizing agents, if the colourless, non-toxic salts of lithium, magnesium, calcium, aluminium or zinc are used as oxidizing catalysts. |