Union Pacific Challenger Passenger car colors

[Pizzaparty]

OK, I could use some help with my research. I have a few 3d prints that I can use for the articulated diners, and stand ins for most of the other cars. But i am having a hard time figuring out were the streamliners that were kicked down to the challenger left in UP armor yellow and gray or were they repainted? Im shooting for the mid 30s challenger.

I found the following consist information -

Lightweight equipment built for "The Challenger" trains in the 1930s and 1940s includes:

UP 5100-5104 Articulated Dormitory-Kitchen-Diner
UP 5200-5211 Women's Chair Car
UP 5300-5327 Chair Car
UP 5351-5365 Chair Car
C&NW 6132-6147 Chair Car
C&NW 6160-6166 Women's Chair Car
SP 2414/15, 2416/17 Articulated Chair Car
SP 2424-2429 Chair Car
SP 2489-2491 Chair Car

I think Union Station and a mix of 3d printed and kato cars should satisfy my needs, but I am struggling with paint schemes. Im finding mixed information between armor yellow/brown or yellow gray or pullman green.

Any and all help is appreciated

[Mark5]

I guess the year you are modeling is important here - some info: https://utahrails.net/pass/pass-paint.php

[Pizzaparty]

I’m shooting for mid to late 30s. So it looks like they would be olive green. But it looks like this equipment was used on other trains, so I’m guessing I can mix and match with my current equipment in yellow/brown configuration. At least that’s how I am reading the articles unless I’m not interpreting things correctly