Abstract: The present invention relates to a process for the oxidation of sulphur dyes, particularly when they are incorporated in natural or regenerated cellulose textile fibres such as cotton, which employs an alternative oxidant to the ecologically undesirable dichromate now used. The process employs two steps, in the first of which the sulphur dyed textile is contacted with dilute hydrogen peroxide, very conveniently having a pH of 3-5 and at a temperature of from 40-80.degree. C. and in the second step, the textile is then contacted with a dilute solution of activator often ferric sulphate, preferably at pH 3-4 and from 0.1 to 1.0 g/l activator concentration. The process can be effected with relatively minor alteration or addition to existing equipment.