Santa Fe Coach Green is different from Pullman Green. As with just about anything related to colors in model railroading, getting the right shade involves many variables and opinions.
Updated May 2015: After much experimenting — and painting/stripping the baggage-express three times, I’m using the following colors for Santa Fe heavyweight cars.
A. Sides, end, steps, battery box covers: gloss A.T. & S.F. Coach Green
2 parts Polly Scale Pullman Green + 4 parts Polly Scale GN Empire Green + 1 part Polly Scale Reefer Yellow, thinned with distilled water. Airbrushed with Badger 150 using a III needle and head at 15 psi.
When dry, sprayed with Testors One Coat Lacquer clear gloss from spray can to provide a gloss finish for decals.
After decals, several coats of Testors One Coat Lacquer clear gloss from spray can. One coat of Testors Model Master 1959 Semi-Gloss clear from spray can.
Here are some formulas from others: see http://atsfrr.com/resources/Sandifer/Pass/CoachGreen.htm
B. Roof: Rustoleum 2089 Dark Gray Primer from spray can.
C. Center sills, air tanks, brake cylinders, water tanks (some cars): Semi-gloss black
D. Underbody except as above: semi-gloss A.T. & S.F. Truck Brown
Floquil Rail Brown from spray can.
Polly Scale Grimy Black brushed onto visible areas of underfloor equipment
Polly Scale: GN Empire Green. I painted the trucks on my baggage-express with this then sprayed on two coats of clear (Pledge/Future) and it looks good.
E. Interior: To be determined, probably will vary by car.
E. Window shades: Brown per P. 13, Santa Fe Painting and Lettering Guide, Hendrickson (C.H. note: LaserKit #382 buff should be OK)