Use of a mineral compound based zinc and/or non-nitrogenous organic compound based zinc as agent allowing for the protection of the color of keratinous fiber colored by direct dye or by oxidation dye in the presence of an oxidizing agent from the effect of washing, is claimed. Independent claims are included for: (1) a process for protecting the color of the keratinous fibers, preferably hair colored artificially from the effects of washing, comprising applying a composition comprising the mineral compound based zinc and/or non-nitrogenous organic compound based zinc, in a medium on the fibers; (2) a process of coloring of the human keratinous fibers, preferably hair, comprising applying on the fibers, a first direct dye composition or oxidation composition in the presence of oxidizing agent during a sufficient time to develop the color, and applying a second composition containing the zinc based compound in a medium; and (3) a multi-components coloring agent comprising: a first component containing the direct dye or oxidation composition, and a second component comprising the second composition containing the zinc based compound in a medium; a first component containing a composition comprising the direct dye, a second composition comprising the composition containing the oxidizing agents, and a third component comprising the second composition containing zinc based compound in the medium; and a first component comprising the composition containing oxidation base and optionally the coupler and/or direct dye, second component containing the composition comprising oxidizing agent, and a third component containing the second composition containing the zinc based compound in the medium.