The seventh-generation S650 Ford Mustang made its official debut on September 14th, in front of over 1,000 fans, media, and influential people. That evening, Ford also revealed a new Mustang performance variant, calling it the Dark Horse. This new Mustang even has its own unique badge and body work to separate it from the rest. But you may not have been able to see much of the details from the original blue/black show car. Enter Ford North America Product Communications Director, Mike Levine, who just shared a picture of the Dark Horse on Twitter wearing an all white dress. Now the contrast be…