When treating stains, it is vital to know whether a textile is colour-fast or not. That is why we always recommend performing a colour fastness test before applying stain removal products. Simply soak a clean, white cloth with some Stain Devil solution and dab it onto an inconspicuous spot of the textile e.g. the inside hem of the garment. The white cloth should remain white, unaffected by the coloured fabric. Provided neither the colour nor the structure of the fabric has changed following exposure to the fluid, washing and drying, you can safely proceed with stain removal treatment.