I'm going to depart from my usual scenery-focused submissions, here, and follow the lead of several voices who have featured their motive power for this weekend's treats.
Black steam locomotives are my favorite, in real-life RRs as well as on the layout...
but when I am in the mood for colorful livery, these are several of the locomotive combinations I run on a particular pair of parallel, neighboring tracks, for their color and flash (!)...