Process for lightening or for simultaneously bleaching and dyeing keratin fibres

A method for lightening keratin fibers, comprising applying to the keratin fibres a composition comprising:

• i) at least one chemical oxidizing agent chosen from hydrogen peroxide, a hydrogen peroxide-generating system other than a peroxygenated salt, or mixtures thereof;
• ii) at least one compound chosen from a carbonate, a carbonate-generating system, a bicarbonate, a bicarbonate-generating system, or mixtures thereof;
• iii) at least one silicate;
• iv) at least one organic acid;
• wherein the total amount of silicate ranges from 1% to 40% by weight, relative to the total weight of the composition;
• and
• wherein the composition comprises a total amount of persulfates of less than 5% by weight, relative to the total weight of the composition.

A method for lightening keratin fibers, comprising:

• (i) mixing a composition (A) with a composition (B) and optionally a composition (C), wherein composition (A) comprises:
• at least one chemical oxidizing agent chosen from hydrogen peroxide, a hydrogen peroxide-generating system other than a peroxygenated salt, or mixtures thereof;
• and
• optionally at least one organic acid;
• wherein composition (B) comprises:
• at least one compound chosen from a carbonate, a carbonate-generating system, a bicarbonate, a bicarbonate-generating system, or mixtures thereof;
• at least one silicate;
• and
• optionally at least coloring agent chosen from a direct dye, an oxidation dye, or mixtures thereof;
• and
• wherein composition (C) comprises:
• at least one coloring agent chosen from a direct dye, an oxidation dye, or mixtures thereof;
• and
• optionally at least one organic acid;
• and
• wherein composition (A), or at least one of composition (A) or composition (C) when composition (C) is present, comprises the at least one organic acid;
• and
• (ii) applying the mixture to the keratin fibers.