| abstract |
The invention provides a hair colouring composition comprising one or more developers selected from amino aromatic systems capable of being oxidised and thereafter undergoing at least two electrophilic attack reactions, and one or more couplers selected from compounds of the formula (I) in which X is a non-leaving substituent, and Z is an active leaving group, and Y is an active leaving group or a non-leaving substituent, such that in the presence of an oxidising agent the or each developer reacts with the or each coupler substantially only at the position having the active leaving group Z and, if Y is an active leaving group, Y, provided that if X is phenyl then Y is not ethyl or methyl. The application also claims compositions comprising a developer and specific compounds of formula (I). |