coating composition may be renewed using techniques such as buffing burnishing cleaning or by applying a suitable restorer e g a floor finish restorer when stained by an iodine containing product excess iodine containing product preferably is manually removed e g by wiping decolorization of any remaining stain will take place over the course of the next few minutes hours or days a longer period of time typically may be required if the coating composition has already been subjected to several stain decolorization cycles during decolorization the stain can be masked by applying to the stain a composition containing starch as described in the above mentioned u s pat no 6 756 349 b2 such masking causes a change in stain coloration from a yellowish hue towards a bluer hue for a normal viewer the thus masked stain typically will be much less objectionable than the original stain this will be so even if masking makes the stain dark blue because the shift to a bluer coloration will also be perceived as making the stained surface cleaner the invention is further illustrated in the following non limiting examples in which all parts and percentages are by weight unless otherwise indicated a conventional floor finish taj mahal u2122 floor finish commercially.