Coloration process

A process for the continuous colouration of aromatic polyester or cellulose triacetate textile materials which comprises continuously applying to the said textile materials a disperse azo dyestuff wherein an aqueous dispersion of the disperse azo dyestuff is padded onto the textile material or a thickened printing paste is applied to the surface of the textile material, the dyestuff then being fixed on the textile material by steaming it at a temperature between 100.degree. and 180.degree. C. or baking it at a temperature between 160.degree. and 220.degree. C., the disperse azo dyestuff being free from carboxylic acid and sulphonic acid groups and being represented by the formula:

• A--N=N--E
• wherein A is the residue of a diazotisable aromatic amine A--NH.sub.2 and E is the residue of a coupling component which is an aromatic or heterocyclic amine, an aromatic hydroxy compound, a pyrazolone or an active aliphatic methylene compound, each dyestuff containing a single carboxylic ester group and at least two cyano groups, and subsequently giving the coloured textile material a treatment in an aqueous alkaline bath which does not contain a reducing agent at a pH above 8 and at the temperature between 50.degree. and 85.degree. C.