Abstract: A process for preparing light-colored aqueous surfactant compositions containing 10% by weight to 60% by weight, based on the total composition, of one or more alpha-sulfo fatty acid disalts (A) of general formula (I), R1CH(SO3M1)COOM2??(I), in which radical R1 is a linear or branched alkyl or alkenyl radical having 6 to 18 carbon atoms and radicals M1 and M2, independently, are selected from the group comprising H, Li, Na, K, Ca/2, Mg/2, ammonium, and alkanolamines, and water, in which fatty acids of the general formula (Ia), R2CH2COOH??(Ia) in which radical R2 is a linear or branched alkyl or alkenyl radical having 6 to 18 carbon atoms, (i) are subjected to sulfonation with gaseous sulfur trioxide, (ii) the acidic sulfonation product is neutralized, and then (iii) is subjected to bleaching with hydrogen peroxide at a pH above 7 in a temperature range of 80 to 95° C.