1. It will be the same "white" as your truck. The color pigments will be matched using the factory formula of your paint code. If your paint has metallic flakes, so will the Xtra.
2. White will be underneath. Also, Xtra contains a Kevlar micro pulp and is stain and scratch resistant.
If you get white, keep in mind that the bedliner has a texture and will tend to hold dirt, sand, and other stuff. So, if you decide to get white, you might want to consider a tonneau cover. Otherwise, you'll probably need to wash it off occasionally so that it will look clean.
EDIT: White and yellow are a real pain and we charge extra for those two colors.
