The color varies based upon what decade you are modeling. Originally it was "Aspen Gold", a yellowish-orange color that is supposed to represent the Aspen trees during the fall. In later years, and mostly after the Rio Grande Zephyr era, the color changed to more of an orange shade. Most commercial paint sellers have the Aspen Gold color.
My son has the book Zephyrs Through the Rockies about the Rio Grande Zephyr. That train ended during 1983. After that, the Rio Grande business train and the ski train cars basically changed over to the more orange shade that is not really Aspen Gold anymore, but is used today.
For today's orange color, look at photos of some of the currently available brand new Walthers Rio Grande passenger cars--but that is NOT the color that was being used during the 1960's (except on some cabooses at the end of the decade that were solid orange).
John
Hi say what color paint is the Ho Rio Grande F7A I know it's silver but the other color?Is it light orange or yellow hard to tell for me? I plant to paint one for the Rio Grande.Ski passenger train I am making,here is a photo of the 1st car I made, https://ibb.co/Dr9nbjt