Prototype modeling - how far can you take it?

[nachoman]

but I plan on using red, yellow, blue, black, and white to experiment until I've found an appropriate base of freight or passenger cars.

i wish you good luck with that - and guarantee you will learn something about paint pigments in the process.When it comes to paints - mixing yellow and blue does not make green. Instead, you will come up with something that looks more like vomit green or greenish brown, or something that looks more like a dirty yellow or a dirty blue. If there was such thing as a true primary color paint pigment, the mixing station in your paint department would only need to stock 4 colors (the primaries plus black to add to a white base) and artists would only need 5 colors on their palette (they also need white to uses as a tint). Unfortunately, the pigments are typically natural materials derived from metal oxides or salts and biologic substances (titanium white is titanium dioxide, white in color, and cobalt blue is cobalt salt -blue in color)

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In reality, the available paint colors is no where close to infinite. Any historical color would have to be recreated by mixing the various pigments that were available at that time. For mixing color for a pre-1900 freight car, it would be wise to start with paints that uses the same pigments that were available at that time. It may turn out the pigment used in your modern yellow, red, or blue paint is a modern pigment and impossible to mix in such a way as to create a historical color. My guess is the paint for a freight car or industrial building was one particular pigment mixed with one particular binder (that binder may also influence the color), thus the prevalence of red and black freight cars. Those websites I posted came as a result of a very quick google search, but a little more research should give you a timeline as to when certain pigments became available. Artist colors typically are sold by their pigment name for the most basic colors, and the paint line also includes blended colors of two or more pigments, or tints or hues of various pigments. Many painters are very conscious of what pigments are in their paints because they need to know how those pigments will interact. For that reason, manufacturers of the higher end artist colors often advertise the pigments they use:

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For craft paints, the colors are usually names with some kind of cutesy or descriptive name, like "barn red". The recipe for the pigments that went into that color is much more cloudy, giving the potential that mixing that color could lead to unexpected results.