Dedicated to Sharing the Heritage of Redwood Empire Railroading
Thank you, powerpawsnw, for your comments.
With no color chips preserved, I'll attempt some educated guesses.
Since redwood figured very prominently in, "The Redwood Empire", I'll submit that the dark green was closely matched to the foliage of the redwood tree. In Fred Stint's book, NWP, vol 1, page 141, we find Nos. 52 and 53. No. 52 seems to have little contrast between the greens, but the shadows are well-lit, indicating a bright, overcast day-great for showing detail, but rough for reading gray tones. No. 53 shows much more contrast, indicating a sunlit image-much better for reading gray-tones. Your statement that the light green may been a sort of jade is very logical. I think we are pretty safe with the boiler being a metallic blue-gray.
I am, by no means, good at reading gray-tones, so if anyone can add to this, your comments would be most welcome.