Steam locomotive - Colouring.

It's a complicated palette. From what I've seen, SAR locos were painted gloss black, sometimes with a silver smokebox (the front section of the engine, where the stack is located). Obviously, the gloss would be lessened by road dust and the grime of daily operation.  If the engine is old or has seen a lot of service, this might be faded to more of a flat black by a combination of  age, weather and dirt. Different areas of the engine might be streaked with shinier spots of oil/grease or duller spots of grime. The color of the firebox (near the cab, where the fire is) might be more faded, I assume due to the temperature gradient. On top of that, I've seen older, hard run locos that have faded to an almost gray color. Your best bet would be to find a picture of a prototype that you want to emulate and use that as your color guide.

Rhino, almost always locomotives lose they're glossiness when they're in service, having said that, I might try a mix of Tamiya gloss black with some Tamiya flat German grey. The grey will tone down the shiny black and give it a weathered look. You may have to play with the mixes a bit. I hope it helps. Heres a photo of a Tamiya german grey with some flat black. This may be to flat for what your looking for, but mixing the grey with a gloss should work. 

All the best, please post some photos it sounds like a real ambitious project.

Steam locomotives were frequently bathed in steam.  The steam would condense on the cooler surfaces of the locomotive exterior, and create various shades of gray, anywhere from very light to very dark, so the whole range of grays might be present. In addition, being frequently doused with condensed water, rust was always a problem, so there would be rust deposits in various places.

On the grays, you have two choices- mix your own, or buy ready-made dirty, grimy blacks.  Floquil made a couple of nice grimy and dirty off blacks.  Many brands of hobby paints have some nice rust colors.

Don I have some Floquil, specifically the Grimy Black. Its a perfect color for locomotives, especially all those dirty undercarriage spots. I need to find more.

Terry

Don this is probable better off-line, but have you tried any of the Doctor Bens Stains. I tried the Creosote for railroad ties and found it to be like thinned india ink, maybe its supposed to be that way. Not bad though. Terry

I think those stains work best on wood, not so well on plastic or metal.  They can be used over paints, but I think weathering powders are better for that.

Thanks

Ah , Yes :

  Your train should reflect her years .If so Blacksmithin is right on the money  .Now if new is what you want the palette is , Gloss black , Anthracite Black , Semi Gloss Black and Radiator silver for the front of the boiler and stack . Our engine on display has a silvered firebox . One more color is a mix of gloss Black with a tint of dark brown .Where greased parts got hot and it left a glossy sheen behind .

      Now the Greys , of which there many after years of service would best be shown with Dk. Panzer grey , Meduim dark steel and probably Gunship Grey for the running gear . Don't forget rust in areas that didn't move !