Disclosed is an ink composition comprising (a) an aqueous liquid vehicle, and (b) a colorant which comprises an anhydride copolymer having at least one chromogen covalently bonded thereto and at least one ester, amide, imide, or thioester group covalently bonded thereto, said colorant being soluble or dispersible in the aqueous liquid vehicle. Also disclosed is an ink composition comprising (a) an aqueous liquid vehicle, and (b) a colorant which is the reaction product of (1) an anhydride copolymer, (2) a chromogen having one and only one group per molecule selected from the group consisting of --OH, --SH, primary amino, and secondary amino, and (3) a material selected from the group consisting of nonchromogenic monofunctional alcohols, nonchromogenic monofunctional thiols, nonchromogenic monofunctional primary or secondary amines, and mixtures thereof, said colorant being soluble or dispersible in the aqueous liquid vehicle.