Mike,
Depending on the date of the image it is likely Coach Green (not Pullman Green) but it could be a brown Pullman Color shade if it is before SP took control. Starting in 1902-1903 the Southern Pacific repainted equipment to Coach Green (SP CS-1) which is closer to GN Empire Builder Green than "Pullman" Green.
This color card will give you the standard SP coach (body) colors from 1887 on into the 1930s:
SPC Coach 39 Paint Card. There is a slight error on this card, I called out "Pullman Color" for the 1893 - 1902 when it was called "Dark Olive" by the SP.
The lighter colored letter board is an optical illusion created by light and varnish, it would have been the same color as the body.
Andrew Brandon
A fixture here since Y2k.
[
www.pacificng.com]
[
www.spnghs.org]
"An end to red domes in our lifetime!"