Walter, if you have a scrap piece of track. I would mount it to a scrap piece of wood and whatever your using for roadbed. Take it outside and hit it with some paint. Mask it off and even try a few different colors. Ballast it and you can even try a few different ones. Take it to the layout room and place it on the table and decide where you want to go with it. Often times colors painted outside may not look the same inside.
There have been a lot of photos posted on weathered trackage. Most are Gargraves, Atlas, or MTH with a flat rail top. The K-Line although it has ties is more in line with tubular track. That’s why I suggested doing a sample piece as you may not like the look.
Early on I painted the side of the rails a Poly Scale brown. Then I would give a thin mist of Grimy Black straight down from the top. Looked rusty and grungy when done. If you model more of the steam era. The rails weren’t a orangey rust. More of a light brown almost greenish look. I recently redid my yard trackage. You can see the difference between weathered and shiny.
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