Anthrapyridone compound or salt thereof, magenta ink composition and colored product

An anthrapyridone compound represented by the following formula (1) or a salt thereof:

• {wherein, R1 represents a hydrogen atom, an alkyl group, a hydroxy lower alkyl group, a cyclohexyl group, a mono- or di-alkyl amino alkyl group or a cyano lower alkyl group, R2 represents a hydrogen atom or a methoxy group, and R3 represents an alkyl group (said alkyl group may have a substituent selected from the group consisting of a sulfonic acid group, a carboxy group, an alkoxycarbonyl group, an acyl group, a carbamoyl group, a cyano group, an alkoxy group, a phenyl alkoxy group, a phenoxy group, a hydroxy group and a nitro group), an aryl alkyl group or a heterocycle-substituted alkyl group (said aryl and said heterocycle may have a substituent selected from the group consisting of a halogen atom, a nitro group, a cyano group, a hydroxy group, a sulfonic acid group, a substituted or unsubstituted alkyl group, a carboxy group, an alkoxycarbonyl group, a carbamoyl group, an alkoxy group and a phenoxy group), respectively}.