The present invention therefore relates in particular to an aqueous cosmetic composition comprising one or more fatty substances in a content ranging from 40% to 80% by weight, relative to the total weight of the cosmetic composition, one or more oxyethylenated fatty alcohols having a number of oxyethylenes less than or equal to 10, one or more alkylpolyglucoside-type surfactants; the present invention also relates to using the cosmetic composition in an oxidative coloring or bleaching method for keratin fibers, particularly human keratin fibers such as hair.