A method for inhibiting dye transfer between items of laundry in a fabric treating appliance including a treating chamber for receiving the fabric items for treatment according to a cycle of operation, the method including supplying liquid to the treating chamber to form a liquid mixture comprising the liquid and free dye molecules and dye absorbers in solution or in suspension within the liquid mixture. At least one of ultraviolet (UV) or visible light spectroscopy may be conducted on the liquid to define at least one of an absorbance or fluorescence value indicative of a level of at least one of the dye absorber or complex in the liquid.