Unfortunately most of the foam cleaners seem to turn tires a brown colour after several applications. Michelin tires seem to be less susceptible to this because of Michelin's Durablack technology. They claim it will keep the tires black without the necessity of cleaners etc.. Personally I think they still need a cleaner/tire dressing.Sunday Rider said:
http://www.canadiandriver.com/articles/pw/carcare.htm