Rio Grande standard gauge steam loco paint schemes

I would like to know what shade of green the D&RGW used on their steam loco boilers, c.1930’s. Any help or information would be greatly appreciated. Thank you all for your time,
Mike

If you can locate the huge book on the history of the Rio Grande (sorry, I don’t recall the title…boy do I miss my library that burned up when my house burned down!) it has some color pictures including some of faded engines. It looked a little lighter than GN, maybe w/ some light grey added to it. Really a guess and by golly w/o the pix.

Some painters have used the GN green for the D&RGW color, since it is hard to tell what the actual color was from color prints in the late 1930 era. Add in the mix of grime and soot, and it is hard to tell what actual color to use.