What shade of orange did the SF use to paint it's reefers? Here is a link to a pic I found on the Fallen Flags website. http://rr-fallenflags.org/atsf/sfrd10145ava.jpg
Check the color charts of the major MR paint companies as at least one has to have the Santa Fe reefer orange. You could even ask the model makers what they used. Hope you're not going to use that picture as a reference. LOL
According to the Santa Fe Painting and Lettering Guide from the Santa Fe Modelers Org., yellow-orange is the color for the reefers. It gives the following formula's: 1)Floquil, 4 parts RR-30 Reefer orange and 1 part RR-31 Reefer Yellow; 2)Scalecoat, 4 parts #16 Reefer Orange and 1 part #15 Reefer Yellow; 3)Accu Paint, #21 Maine Central Harvest Yellow. Hope this helps. Jerold