I have two 3 Unit sets of these shells one as the City Of San Francisco SF 1 SF 2 SF 3 and the other as the City,Of Los Angeles LA 1 LA 2 LA 3. Yes these locos were originally Armor Yellow and Leaf Brown with red striping. In 1941 when the E-6 diesels arrived and new passenger cars with bright chrome strips above and below the windows the Brown was changed to Harbor Mist Gray. Passenger cars on the 1937 trains had brown not gray roofs and skirting. These cars were semi-articulated. Your best very complete source of information on these trains is the massive 592 pp. book "The Union Pacific Streamliners" by William Kratville. Kratville Publishing (c) 1974. The Porthole Products shells are some what crude, the detail is rather shallow so paint covers it unless you use thin coats. These shells originally were designed to fit the old Roco Atlas E-7 drive ,which is what I used at first. The newer Life Like E-6/7 drive will work. Originally I had my locos with one A and one B powered and one dummy B. I have Redone one A-B loco so far with Life Like Drives,left one dummy have not yet converted my other set. Trucks on these diesels were originally Brown like passenger car trucks. These were changed to Gray in 1941. If you have gray & Yellow cars, then paint your loco with Gray it would look better than a Yellow & Brown loco pulling Yellow & Gray cars. I used Bare Metal Foil (rubb on) to do the chrome nose hearald back grounds. My decals were the old Walthers N sets for these locomotives before Micro Scale offered them. My last word be careful when filing on the shells, they can break really easly as the castings around fuel tanks and skirtings are very thin.Headlights can be slowly drilled out to avoide cracking the nose. Nate Goodman (Nato). Salt Lake, Utah.