We can apply a specific color to all highlighted sections of track in SCARM. So it just comes down to how we highlight the sections of track. If we hold down the <shift> key and click multiple times on a single section of track, then all sections of track with the exact same number will be highlighted and a color can be applied. This is not by length because there are several numbers that are the same length and you would need to repeat it for each number. For 1-3/8" track, there is a different number for no roadbed, half roadbed, and full roadbed. For 10" track, there is a different number for regular track, a couple types of terminal sections, a couple types of accessory activator sections, and an operating section. For 5" track, there is regular, a couple types of insulated, an uncoupler, and a transition piece.
This is not too bad because you are not using all of these different model numbers in one layout. However when I tried using your approach with a simple layout using different radius curves to simulate track easement, I started getting dizzy:
One of my favorite features with SCARM is the parts list that it generates. But all the work I did with coloring the different types of track did not show up on the parts list.