A permanent hair color altering composition comprising an aqueous preparation on the basis of melanin dissolution and/or oxidation of a hair colorant dye intermediate, which contains as a swelling and penetration agent, a quaternized amino lactam having the formula: ##STR1## wherein m is an integer having a value of from 1 to 4; R is alkylene having from 3 to 8 carbon atoms and is optionally substituted with C. sub. 1 to C. sub. 4 alkyl; R. sub. 1, R. sub. 2 and R. sub. 3 are each independently selected from the group of alkyl, alkyleneoxy alkyl, alkylhydroxy, alkoxy, aryl, aralkyl, alkaryl, and alkylene amidoalkyl radicals, said groups each having from 1 to 30 carbon atoms and at least one of R. sub. 1, R. sub. 2 and R. sub. 3 is a radical having from 8 to 30 carbon atoms; and X. sup. - is a chloride, bromide or iodide anion.