I read somewhere that they gave a lot of power to the riders in deciding what their bikes would be like, this may have included the color scheme. It would make sense that it is the idea of a few racers as opposed to some stylist who surely designs the other team rides. Plus, if you hadn't noticed, they are going for the "all-american" look. They definitely have faith in the American fan base and are trying to win their support.
What the heck......GO TOYOTA-UNITED!!!