I think my vote is for the gold/yellow like Durango for all the regular cars, and green for the parlor cars which is the old color of the San Juan cars. The yellow does have D&RGW heritage and they stand out in the countryside, and look bright and cheerful to riders. Hey, it must work for the D&S all these years. While I like authentic, the green is rather drab, and sort of reminds me of an army troop train, which most vets hated!
So, either make the parlor cars green or yellow like the all of them. Spruce up the train, and we might actually get some folks thinking this is Durango by mistake and they will stay in Chama or Antonito instead!
As John noted, spice up the Parlor car with a little extra scroll-work, or pinstriping to make it look First Class.
Greg Scholl