Thus, cyan couplers usable in the invention are preferably compounds represented by the following formula (C-I): wherein R3 and R4 are each a hydrogen atom or an alkyl group; R5, R6 and R7 are each a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom; Y is a hydrogen atom or a group capable of being released from the coupler upon reaction with an oxidation product of a color developi