I've applied Neolube on several HO steam locomotives of mine which had main rods, side rods, and valve gear which was so bright and shiny that I couldn't stand how they looked. Now they look like engines which have been running for a while. I did notice that the darkness depends upon how many coats of Neolube are used. I does rube off when handled, so I am careful how I pick up the engines, but otherwise I am very happy with the results, especially that I don't have binding problems like I would have if I used paint.
Stuart