Adding soot effects to track?

[Bob C]

It might be that this unweathered track may be a main track, and have just had maintenance done. Such work often disturbs, cleans or replaces ballast, eliminating the weathered look...the sleepers are grey-ish (stone dust) and the clean stone is evenly leveled to the tie-tops. A section of just renewed track would make a great detail vignette with a track crew around, or just evidence (tools, hardware containers, etc) of their toils.