The present disclosure relates to an agent for coloring and/or bleaching keratin fibers, consisting of: a first composition (A) comprising at least one alkalizing agent, and a second composition (B) comprising at least one oxidizing agent, wherein at least one of the two compositions (A) and (B) comprises at least one fat selected from liquid hydrocarbons, such that the at least one fat is present in a mixture of compositions (A) and (B) in an amount of at least 20 wt. %, relative to the total weight of the mixture, and further wherein at least one of compositions (A) and (B) comprises at least one reductone optionally in a form chosen from acids, salts, and esters. The present disclosure also relates to a method of coloring and/or bleaching keratin fibers employing the agent, as well as a kit containing it.
