The present invention relates to a process for removing hair colour from hair keratin fibers which have been coloured beforehand, comprising the application of at least one colour-removing composition to said hair keratin fibers which have been coloured beforehand using at least one hair colouring composition comprising: at least one (poly)carbodiimide compound; and at least one colouring agent chosen from pigments, direct dyes and mixtures thereof; said colour-removing composition comprising: at least one surfactant, preferably a cationic surfactant; and at least one polyol.