A method for lightening keratin fibers, wherein the method comprises the following method steps in the sequence indicated: a) applying a brightening agent (AM) to the keratin fibers, which brightening agent is prepared immediately before application from at least one cosmetic agent (M1) and at least one oxidizing agent preparation (M2), b) leaving the brightening agent (AM) prepared in step a) on the keratin fibers for a time of from 10 to 60 minutes, preferably from 20 to 45 minutes, at room temperature and/or at least 45 °C, c) rinsing the keratin fibers with water and/or a cleaning composition for 1 to 5 minutes, wherein the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) contains, in a cosmetically acceptable carrier, a. at least one dimethylcyclosiloxane of formula (I) in a total amount of from 1.2 to 4.5 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which z represents integers from 3 to 12, and b. at least one polydimethylsiloxane of formula (II) in a total amount of from 0.2 to 1.0 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which n represents integers from 1,800 to 28,000, and wherein the weight ratio of the at least one dimethylcyclosiloxane (i) of formula (I) to the at least one polydimethylsiloxane (ii) of formula (II) in the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) is 6:1 to 4:1. a) applying a brightening agent (AM) to the keratin fibers, which brightening agent is prepared immediately before application from at least one cosmetic agent (M1) and at least one oxidizing agent preparation (M2), b) leaving the brightening agent (AM) prepared in step a) on the keratin fibers for a time of from 10 to 60 minutes, preferably from 20 to 45 minutes, at room temperature and/or at least 45 °C, c) rinsing the keratin fibers with water and/or a cleaning composition for 1 to 5 minutes, wherein the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) contains, in a cosmetically acceptable carrier, a. at least one dimethylcyclosiloxane of formula (I) in a total amount of from 1.2 to 4.5 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which z represents integers from 3 to 12, and b. at least one polydimethylsiloxane of formula (II) in a total amount of from 0.2 to 1.0 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which n represents integers from 1,800 to 28,000, and wherein the weight ratio of the at least one dimethylcyclosiloxane (i) of formula (I) to the at least one polydimethylsiloxane (ii) of formula (II) in the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) is 6:1 to 4:1. a. at least one dimethylcyclosiloxane of formula (I) in a total amount of from 1.2 to 4.5 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which z represents integers from 3 to 12, and b. at least one polydimethylsiloxane of formula (II) in a total amount of from 0.2 to 1.0 wt.%, based on the total weight of the cosmetic agent (M1) and/or the oxidizing agent preparation (M2) in which n represents integers from 1,800 to 28,000, and <EOS>