The invention relates to a method for determining the color of a cosmetic product on a skin model, the method including steps to: - for a plurality of wavelengths, supply experimental points giving diffusion and/or absorption values for several mixes of a given concentration of one pigment in another pigment, each mix corresponding to different given concentrations, and - use a physicochemical model capable of predicting interactions between pigments passing through experimental points to obtain the curve giving the diffusion and/or absorption for each wavelength as a function of the given concentration of pigment in the mix of pigments considered.
