What general years where these paint combonations in use. My specific area is Wyoming.(If it matters)
Black/graphite 19??-19??
Gray w/ yellow lettering 19?? -19??
Gray w/ white letering 19??-19??
I don’t claim to be an authority on the Greyhound paint scheme (a name I originally coined for whatever that’s worth) but I had a copy of the UP blueprint at one time (sadly lost in a house fire w/ lots of other goodies) so I’ll try to start things off from memory and any more knowledgeable UP fans can issue corrections. The grey paint went on immediately after WWII w/ grey striping to match the paint on the Overland and City of St Louis. I’ve seen pix of 800 class Northerns in grey before the smoke deflectors were added. The striping and lettering went yellow after UP decided to paint all psgr cars in yellow and back to black sometime around the early 50s. Not very precise, but maybe somebody can narrow it down better.
There’s some debate over which Two Tone Gray scheme came first (silver lettering and striping or yellow). There’s some evidence to suggest the silver came first (1946 or earlier), but nothing concrete that I know of. Yellow was in use from late 46 until mid-49. Then silver from mid-49 until going back to black paint in 1952. These are the policy change dates, the actual repaint dates would follow these by months to years.
This is a long time running disagreement amoung UP fans. The UPHS did a great article on the two tone gray scheme several years ago and I agree with that article.
The first two Tone Gray paint used the yellow stripes starting in 1946 and a great color picture of the 839 in 1946 shows the yellow stripes. No one is actually sure how long the yellow was used, but the last engines in the two tone gray including some MT-73 in the scrap lines still had the silver stripes. There are many pictures in color of the two tone paint scheme on MT-73’s in helper service on Cajon pass in 1950 that clearly show silver stripes. By late 1953, all of the engines were being repainted in black and alumium again and the two tone gray was not used any longer.
You can use either color stripes on two tone gray engines for the change over period which seems to be between 1948 or 1949. Each engine would have been repainted only during a major shopping. Black and white pictures cannot be used to try and determine the color of the stripes. Every color picture available that I have looked at after 1950 or so used the silver stripes. I personally own about twenty Union Pacific books, many of which have color pictures and this along with the UPHS article is what I am basing my opinion on.
I model the two tone gray FEF’s with both silver and yellow stripe versions since the UP did paint them both ways at one time and I still use a modelers license.
I hope this helps but I am sure other will not agree with me completely on this.