Abstract: A process for treating fabric and particularly indigo dyed fabric to change its color to a desired shade or cast contacts the fabric with an aqueous solution containing a chlorine-providing compound and an amount of a bromide salt and/or iodide salt. The desired shade of the bleached fabric can be controlled by adjusting the ratio of the bromide salt or iodide salt in relation to the concentration of the chlorine providing compound and the pH of the aqueous solution. In one embodiment, the chlorine-providing compound is sodium hypochlorite and the salt is sodium bromide, potassium bromide, sodium iodide, potassium iodide and mixtures thereof. The salt in combination with the sodium hypochlorite produces a gray cast to the fabric and particularly indigo dyed denim compared to the blue cast of conventional hypochlorite bleaching and reduces the amount of the hypochlorite bleach normally required to attain the desired shade.

Abstract: A method of treating blue or black denim fabric to change its color, a composition used to create the color change, and the denim fabric produced thereby. The composition is applied to the denim fabric in a washing machine and comprises cellulase enzyme, a detergent, a salt, a buffer and dyestuffs. The fabric is either stonewashed before or during application of the composition. After the composition is applied, the resulting denim fabric is stonewashed in appearance and has a surface displaying two sets of light and dark areas of different shades of the same color.