The present invention relates to a dyeing composition comprising one or more acid direct dyes of indigoid type of formula (I) in which n has the value 0, 1 or 2, R1 represents an &mdashSO3M group where M represents a hydrogen atom, an ion resulting from an alkali metal, an ammonium group or an ion resulting from an organic amine, X and Y represent, independently of one another, >C&boxHO, Z below or Z&prime below, Formula (Z) n&prime having the value 0, 1 or 2, Formula (Z&prime) n&Prime having the value 0, 1 or 2, with (*) representing the point of attachment of Z or Z&prime to the remainder of the molecule provided that at least one of the coefficients n, n&prime or n&Prime is other than zero, and one or more organic compounds (II) exhibiting a value for the Hansen solubility parameter &deltaH of between 5 and 16 MPa1/2 and with a molecular weight of less than 250 g/mol. It also relates to a dyeing method which consists in applying such a composition to keratinous fibres.
