The disclosure provides compositions for simultaneously bleaching and dyeing keratin fibers, comprising at least one direct dye chosen from anionic and nonionic dyes, with the exception of 7-(6′-methylphenylazo)-1-acetamido-3,6-disulfo-8-hydroxynaph-thalene, ortho-nitroanilines substituted meta to the amino group, quinoline and quinoline derivatives, and addition salts thereof, at least one associative polymer, at least one peroxygenated salt and at least one alkaline agent, to processes for simultaneously bleaching and dyeing keratin fibers using the compositions, and to uses of the compositions for simultaneously bleaching and dyeing keratin fibers. The compositions are suitable for dark hair. They are easy to use and can produce chromatic and fast coloration.