I have always liked 2-tone on the old trucks but always thought the AD's were only available in a single color. For the earlier trucks this was advertised as an option see below.
http://www.flickr.com/photos/advance-design_parts_co/8334477407/in/photostream
Then I picked up this 1950 Salesman order book and two-tone paint is mentioned as "apply to the zone office"? So is it correct for the AD's? In light of this it looks like you could get any color or combination you may have wanted?
http://www.flickr.com/photos/advance-design_parts_co/8335509364/in/photostream
http://www.flickr.com/photos/advance-design_parts_co/8335509814/in/photostream
http://www.flickr.com/photos/advance-design_parts_co/8334456399/in/photostream/