I just tried out the red arms -- they contrasted very nicely, and made the officers and NCOs stand out. Red legs look okay, but the SF's primary color is blue, and I feel that everything SF should have some blue on it; since swapping legs is a pain, I'm leaving them blue (as is).
Also, something I didn't mention; all of the SF faces are unique and visible! I made very sure that I never repeated a face, and avoided opaque visors (repeated and hidden faces are for cannon fodder; that will come with a different faction).
I'm glad you all like the bunker and vehicles!
Heuristic ALgorithmic AFOL.
T6281: Solar Federation (Rules T6588)
T6777: Dungan Swarm
T6783: Space Pirates
T7349: BrikWars Vehicle Datasheet
T7402: Imperium Constructor