The present invention relates to a composition for dyeing keratin fibers, comprising: a) one or more liquid fatty substances； b) one or more amphoteric surfactants of formula (I) below: Ra′—C(O)—NH—CH2—(CH2)n—N(B)(B′) in which: —B represents the group —CH2—CH2—O—X′； —B′ represents the group —(CH2)zY′, with z=1 or 2； —X′ represents the group —CH2—C(O)OH, —CH2—C(O)OZ′, —CH2—CH2—C(O)OH or —CH2—CH2—C(O)OZ′, or a hydrogen atom； —Y′ represents the group —C(O)OH, —C(O)OZ″, —CH2—CH(OH)—SO3H or the group —CH2—CH(OH)—SO3—Z″； —Z′ and Z″ represent, independently of each other, a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine； —Ra′, represents a C10-C30 alkyl or alkenyl group derived from an acid Ra′—C(O)OH, which is preferably present in copra oil or in hydrolyzed linseed oil, an alkyl group, especially a C17 group and its iso form, or an unsaturated C17 group and —n represents an integer ranging from 1 to 10 and preferably from 1 to 5, —or quaternized forms thereof； c) one or more sulfate or sulfonate surfactants； d) one or more oxidation dye precursors. The present invention also relates to a process using this composition and to a multicompartment device that is suitable for performing the said process.La présente invention concerne une composition pour colorer des fibres de kératine qui comporte : a) une ou plusieurs substances grasses liquides ； b) un ou plusieurs tensioactifs amphotères de la formule (I) ci-dessous : Ra'-C(O)-NH-CH2-(CH2)n-N(B)(B') dans laquelle : – B représente le groupe -CH2-CH2-O-X'； - B' représente le groupe -(CH2)ZY', z = 1 ou 2 ； - X' représente le groupe -CH2-C(O)OH, -CH2-C(O)OZ', -CH2-CH2-C(O)OH ou -CH2-CH2-C(O)OZ', ou un atome d'hydrogène ； – Y' représente le groupe -C(O)OH, -C(O)OZ", -CH2-CH(OH)-SO3H ou le groupe - CH2-CH(OH)-SO3-Z"； - Z' et Z" représentent, indépendamment l'un de l'autre, un contre-ion cationique dérivé d'un métal alcalin ou d'un
