I'm going to go out on a limb and say red. the underside of a bill of a new era hat isn't usually a different color unless the logos and trim are a different color than the basic scheme. plus i think a red hat with a solid white under-bill would look kind of retarded.
I ride longboards almost every day, and i have to say that these shoes are some of the most comfortable rides i've ever had. They are also very durable and will not get battle scars very easily. All in all, an awesome pair of shoes.