While some may find it hard to believe, there was life (and color!) before Pullman Green, boxcar red, and basic black. A friend of mine has set about finding, and posting online, vintage railroad paint suppliers color charts. With his permission, here are links to a couple very helpful pages from his website;
1877 JW Masury & Son Co. Paint Catalog# 1883 H.W. Johns Asbestos Roof, Railroad and Seaside Paints.
More information is available here: Pacific Narrow Gauge dot Com Historical Paint Data
And for those who’ve wondered what planished, or “Russia” iron really looked like: