Railroads/Panz Camp/ low res 2D how to change

[tobruck41]

Got a question for all you mod pros,

I want to highlight rail lines in the Panzer Campaign series at the lowest 2d res.  I don't want to completely overwhelm the hex color (I can already do that and it ain't pretty).

I just want to highlight the hexes just a touch so they are easy to see where they are without totally distracting from all the other features.

Any graphic pro's out there?

Thanks!