Just picked up on this thread...here's my response to your original questions. I spray paint earth, tan, or brown colors to rail already installed. Before it dries, I wipe the tops of the rail clean (almost) with a paper towel. I come back later, uually the next day and use a Brite-Boy cleaner to finish up. If you paint flextrack before it is installed you will have to touch it up on curves after it is laid. For me it doesn't matter that the ties are the same color as the rails, on most of the prototypes near me it's hard to tell if there is significant difference. Here is a picture with some before and after.