Brown Staining on Whitewalls

[8EL]

The brand new AMER CLASSIC RADIAL - 475/500-19 WW tires I bought have brown stains in the whitewall that standard cleaners (kitchen cleanser and brillo pads) will not remove. These tire were purchased last December and left with their shipping wrappers intact until yesterday when I mounted them. There are warnings about not allowing the "black to touch the white" given, but this certainly was not the case here. Was I sent a batch of blems? Has anyone else had this problem, if so what was the resolution?