MOST of the time, watching cars travel the looping highways of Texas cities is like tracking luggage on an airport carousel. Everything looks the same: Silver, white, black. Silver, white, black. Ah, a red one. Standing in a parking lot, it can be hard to distinguish one’s car from the monotone masses. It might be easy to blame the lack of color on the tough times in the auto industry. A few years ago, the industry was selling 16 million to 17 million cars a year. Last year it was about 10 million, said John Felice, Ford Motor Co.’s general...