Rick,
I would guess that the white faces in your model are faces with their front side visible, and the bluish ones are "back" faces. Generally a model should be built so that only the front sides are visible, especially if you plan to use outside rendering apps. See the manual for more explanations. The reason why they are mixed as they are lies either in AutoCad:s sloppy 3DS export or the way SU interprets the vertices of the faces when importing. There is not much you can do about it when importing. If you want to try correcting those, the right-click menu commands "Orient faces" and "reverse faces" are the ones to use.
Anssi