Here are the replies I've recieved at the moment. I'll continue to post more as they come through.
First, I assume you are talking about a larger than HO scale model.
In model scale, there are two brands of paint that I recommend for Southern
Green. One is a solvent based paint and the other is an acrylic. Scalecoat
Southern Green is solvent based paint. The other is Modelfex Southern
Sylvan Green made by the Badger Co and is an acrylic. Both these brands
produce a good representation of the SR Green.
However, for a large scale project, I would recommend painting one of these
onto a chip and taking it to a paint store that has computer matching
capability in order to obtain a large quantity.
Once again, I assume you are talking about a large scale locative.
"If you really want to go all-out, Dupont has a code in industrial Imron for Sylvan Green. It is 42-42N.
The paint used on a Coleman stove or lantern is not paint but a power coat finish. The problem with using that is the boiler will get hotter then what is needed to set the powercoating, which is about 400 degrees. You can get Southern green from DuPont and it is called Southern engine green, but you can't get the old color code that was used on a PS4 engine, they have quit making that type of color.
I am in the same boat that you are in, but I am not ready for painting yet on my two live steam engine, I have the frame finish, and getting ready for the value gear and the rear trucks, and then the cylinder.
I greatly appreciate your help...! I assume probably the older dupont colors were made with a lead based paint.... I found this link http://www.railfonts.com/Reference/paint_cross.pdf To me looking at color photos of the 4501 and the 722 when used by NS for their steam program, the paint looks noticably lighter than the color slides I have seen of the Ps-4s....however this might be due to what Mike was saying about how its 2 seperate colors....I can't imagine though they would use two different colors for the locomotives. The scalecoat is very good paint, I believe you can even buy it in large quantities and it is heat proof. However imron would certainly make a tough finish that would hold up well.
Bear in mind that Southern allowed each shop to maintain its own locomotives, and they ended up with a significant "personality." An expert can readily identify a locomotive from Spencer, Asheville, Knoxville, Atlanta, etc. I don't know for sure, but I would not be surprised if this extended to paint selection as well. There was a specification, but shops may have been allowed to purchase or blend their own paint. Of course, I'll be the first to admit that that is purely speculation.
Another thing to think about is weathering, both of the paint exposed to the elements, and the soot, dust, grime, etc. that coated even the best-maintained locomotives. This couild easily lighten or darken a color, and would be different in different regions, and certianly different for steam vs. diesel locos.
Finally, there could have been a color change, either intentionally or accidentally, between the steam era and the excursion era. I do know that 4610 is not painted correctly, and I seem to recall that the color is off as well as the paint scheme. N&W 611 wore a paint scheme in excursion service which she never had during her revenue days. So excursion locos are probably not the best source of information.
With all that said, I'd pick something you like, and just do it. If anybody complains about the color, tell them they're more than welcome to pay to have it re-painted!
Ah yes the Southern Green paint color , a never ending question , I think Kenneth is correct .
The Princeton Indiana shops and division point was a large installation , and you can still see where the turntable was on the Google sat site .
I remember the Southern Green on the Ps-2s , light 4-6-2s , as being a lighter green than what is normally used in modeling , which could be a local paint color mix , fadeing , how many times it had been wiped down and with what by the engine wipers , and so on .
It may have just been here on the St Louis division , that the cab roof was also like a flat brick red color . No I do not have a photo , wish that I did though , because my dad and others here knew they were red cab roofs here abouts .
So paint it the shade that YOU like , and be happy , because anyone who had seen them for real , back when they were in use normally , is now old , and with fadeing memory just like the paint colors .
St Louis div shops at Princeton In , where the different sand dome , and front end handrail config were known for on the 2-8-0s ,
And why the 2-8-0s were used so extensivily , and the 2-8-2 mikes were in isolated areas on the division
Born in a house so close to the SR main in Oakland City In ,thats its still unbeliveable to me , cinders and coal smoke from the begining .