What was the color scheme of UP passenger cars and steam locomotives just before the coming the diesels?
Steam engines were either black or two tone gray, called the greyhound scheme.Streamliner passenger cars were yellow with gray trim. Heaveyweights were either Pullman green or the two tone gray Overland scheme.
Am I correct in assuming the yellow scheme was not being used before the diesel engines?
I believe the early streamliners were Yellow with Brown the Gray came later replacing the Brown. TYhe lettering was Red. The two tone Gray had Aluminum separation stripes and lettering.
As mentioned the yellow/brown scheme was used on the early Streamliners. Later the "City’ trains got the yellow/grey scheme while other trains were 2 tone grey.
I’ve read that 3 different colors for the seperation stripes and lettering on the greyhound scheme were used on the steam engines depending on when & where they were assigned. Silver was used early on, except on the Norhwest divisions which used white. Later, as more of the general passenger pool was repainted yellow/grey, the stripes & lettering was changed to yellow.
Things got really interesting for a while, when a passenger train might have a greyhound Northern, yellow/grey E8’s or PA’s pulling a mix of 2 tone grey, yellow, SP silver/red passenger cars, possibly even with a heavyweight diner.
The Armour Yellow paint scheme was introduced on the M-10000 distillate-powered streamliner in 1934. It was applied to the 'City" streamliners and to motor cars thereafter, but didn’t become the system standard color scheme until 1952.