Dyestuff (I) comprises powder pigment coated in an organic binder, in which the organic binder is sorbitol, present in the proportion of 1-20 wt.% for 60-95 wt.% of pigments in its total weight composition, (I) further comprises constituents in stoichiometric proportions of an effervescent agent in the presence of water and ethoxylated fatty alcohol as a dispersant, such that (I) is dispersible in an aqueous medium. An independent claim is included for a process for the preparation of (I) made of mineral pigments coated in the organic binder, present in granular form solid at room temperature, comprising: preparing a water soluble effervescent agent by mixing citric acid and sodium carbonate in the form of crystal, in the stoichiometric proportions to give rise to effervescent release of carbon dioxide in the presence of water mixing dry pigments with the effervescent agent, the dispersant comprising ethoxylated fatty alcohols and sorbitol heating the obtained mixture at a temperature of 100[deg] C, for melting the sorbitol and cooling together by subjecting to moderate agitation until completely cooled to avoid the agglomeration into blocks, before sieving the obtained granules of a suitable size for use in the preparation of cosmetics.La présente invention concerne une matière colorante essentiellement constituée de pigments pulvérulents dans un liant organique denrobage dans laquelle ledit liant est à base de sorbitol, dans une composition comportant, en poids par rapport au poids total de ladite matière, entre 60 et 95 % de pigments et entre 1 et 20 % de sorbitol, et comportant en outre un agent à effet effervescent en présence deau, notamment du carbonate de sodium, ainsi quun agent dispersant de la famille des alcools gras éthoxylés, La matière colorante suivant linvention est aisément dispersible en milieu aqueux. Elle se présente sous forme de granulés solides à température ambiante, et sous cette forme, elle est destinée notamment à lindustrie des cosmétiqu
