tis the season and we're off to seatlle and will be gone for a month and a half. we have a recently leased a f150 v8 to tow my 24' tt. but my wife points out the michellen tires have a very dark brown...
It is called blooming. It is caused by the antiozonante that is in the tires to prevent cracking etc. I would not worry about it. You can probaly wash it off but it may come back.