Polyester-based comb polymers obtainable by aza-Michael addition of primary monoamines or primary or secondary diamines on diesters from unsaturated monocarboxylic acids and diols, are included in surfactant-containing aqueous detergent solutions in order to prevent the transfer of textile dyes from colored textiles to uncolored textiles or textiles of other colors when washing textiles together in the detergent solutions.