Track takes on colors of its environment. We mostly see track of a gray-brown rust with gray to creosote blackened ties. But sometimes the colors can be surprising.
This photo feature presents track in the Smokey Mountains of the southeastern United States, along part of Doe River Gorge Ministries' railroad, part of the storied Tweetsie railroad.
This area is frequently damp, mountains shading the line from the sun, with abundant organic matter to attach to metal and wood. Note the green rail.