Thank you both. I had a "well, duh" moment after Wayne's response when I realized the Pennsylvania Lumber Museum had a restored Barnhart, and found related color photos there. Boxcar red seems to have been the popular color with black or gray undercarriage. Peter, the photos in your link are outstanding, wish I had that eye and patience for detail.
Mr. Reisiger says that he has carried out extensive research for his build, I have no reason to doubt him.
https://www.facebook.com/pg/2-SCALE-Professional-Model-Building-Services-by-Peter-Reisiger-180347105336998/photos/?tab=album&album_id=876275562410812
Cheers, the Bear.
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
These are the only photos of real ones which turned up in a quick search (I'm not certain that they're actually Barnharts, either, as the second one appears to be a steam shovel...a conversion, perhaps?)...
This log loader
This one may be a log loader converted into a steam shovel?
This one
While the Marion Steam Shovel Company may have painted them in a standard "factory" colour, or painted them to the buyer's requested colour, I'd guess that you'd be able to paint it in whatever colour you wish.
The boxcar red in the linked photos could be the original colour, but it's more likely to be re-paints by the individual owners, as I'm sure that they must've been dinged-up or otherwise damaged in the rough service in which they were used.
Wayne
I'm in the process of building a Keystone Locomotive Works HO scale Barnhart, but all the photos I've ever seen of one are B&W. Seems like a good idea to paint much of this before assembly. Any ideas on appropriate colors for the shell, roof, and boom, or the various interior and carriage details? Thanks!