Union Pacific issued this paint guide for passenger and freight stations in 1956. The guide includes color chips and references to Pittsburgh paint numbers. Exteriors were to be off-white with Kentucky green trim and wainscoting. Station agents were given a choice of interior colors: sunny yellow, seafoam green, blossom pink (more of a beige), and como blue.
Most of the paint chips seem to have retained their colors, but I question the chip representing Kentucky green as it appears almost black in my scan. As shown below, at least one of the two images of Kentucky green (Pittsburgh paint number 1-338) I can find on line is much lighter.
A close up of the Kentucky green paint chip.
A house with Kentucky green trim, from a 1942 Pittsburgh Paint booklet.