JE: I model the NYOW (proto-freelance) in N Scale. My research revealed that much of the railroad was ballasted with Culm - fine-grained waste from anthracite coal mining. I use a combination of black and grey fine ballast. There are a couple of O&W books that are in color (NYOW In the Diesel Age, is one, I think). Also, there is a lot of information available to members of the NYOW Historical Society (google it), also check out the O&W facebook page.
Joel
I was thinking along those same lines but am considering using both dark and light gray ballast along with the black and throw in a little dirt and weeds as well.
I have the color book of NYOW diesels. I don’t have it in front of me right now so I’m not sure where the photo was taken but there is one in which the grass is so high not only can’t you see the ties, you can’t even see the rails. It looks like the train took a wrong turn and ended up in somebody’s back yard. I’ve got another B&W book from all eras and at the end of one of the minor branches the yard tracks are also in tall grass. I think I want to duplicate that look at the end of my branch.