If you are talking AD's or earlier trucks you could have any color under the sun as factory. Further you would have almost no way to document this without original purchase paperwork. See the image to back-up my statement.
http://www.flickr.com/photos/advance-design_parts_co/8335509814/in/set-72157631872034068/lightbox/1950 salesman order book shows two-tone or special colors as apply to zone. Chevrolet had advertised two-tone or customer colors as early as 1941 model trucks. Paint is a personal preference for sure, there are some standard factory colors that I would never paint a truck because I don't like them. Paint is also a significant investment so you should be happy with it, this is your truck and your money after all.
