Abstract: Process for the coloration of aromatic polyester or cellulose triacetate textile materials which comprises applying to the said textile material by an aqueous dyeing, padding or printing process a disperse dyestuff which contains at least two carboxylic acid ester groups and subsequently giving the colored textile material a treatment in an aqueous solution of an alkali having a pH above 8 and at a temperature between 50.degree. and 85.degree. C, whereby the textile materials are colored in a wide variety of shades possessing very good to excellent fastness properties.