How do you change the color of Bugatti Veyron in Forza Motorsport 3?

I wanted to change the color of my Bugatti Veyron, But the red thing at the side wont change... how can i change the color D:?|||If the option isn't there when you go to paint it then you could go to the storefront and get a vinyl for it.Or make your own vinyl to cover up the red part.(That is what I did)