The present invention relates to a cosmetic composition comprising, in a cosmetically acceptable medium, a dyestuff which comprises a fibrous inorganic matrix comprising tunnels and organic colouring compounds incorporated at least partially into said tunnels, said compounds being chosen from indigoids, and present in an amount such that the colorant/matrix ratio by weight is greater than or equal to 0.028. The invention also relates to a method for the cosmetic treatment of keratin materials, comprising the application of said cosmetic composition.
