I could not find a post about this but I may have been using the wrong search words. Today, I was washing the tires to get the blue chemical removed from the tire (what is on new tires during shipping).
I have tried the following without any luck: Adam's Car Shampoo, Adam's All Purpose Cleaner, Simple Green, and Grease Lightening. Also, I used a very stiff brush.
Always in the past just soap and water brings the blue color off the tires.
So