The present invention relates to a cosmetic composition comprising, in a cosmetically acceptable medium, at least one non-nitrogenous zinc salt and at least one amino silicone, in a weight ratio of the amount of amino silicone(s) to the amount of zinc element ranging from 0.01 to 5, preferably from 0.2 to 3. Another subject of the invention relates to a treatment process for keratin fibres, using such a composition, and the use of such a composition, preferably in the form of a leave-in care product, for conditioning keratin fibres and protecting the artificial colour thereof against fading.
