The best mobile spokesperson for the worst mobile carrier is dropping the pink dress that helped to make her so popular in favor of black leather and a Ducati motorcycle as T-Mobile tries to do something (anything) to rebrand themselves as a player in the mobile industry. 23-year-old mobel Carly Foulkes has been one of the few bright spots in T-Mobiles marketing over the last couple of years, drawing in fans to her personally while attempting to expand the brand’s image. It hasn’t helped sales as much as they’d hoped, mostly because of issues not associated with marketing. Fans of the model will…