Jim,
You can go to Ford's website and click on build your Mustang. You will see that the most expensive package for the GT Mustang is the California Special. Click on that premium package and it will take you to your color choices. The choices are - Black, Race Red, Red Candy Metallic, Deep Impact Blue Metallic, Grabber Blue, Performance White, Gotta Have It Green Metallic, Ingot Silver Metallic & Sterling Gray Metallic. Unfortunately there is only one stripe color and that is Satin Black.
Cheers,
Ron