ComStar

5th Army V-Omicron

The Mountaineers

The Com Guards simply paint their vehicles white for official occasions and use appropriate camouflage for combat.

Per FM: ComStar, page 17.
Other references:
Shootist, CB: Miniatures Rules (p 23)
Color Scheme
Insignia
The insignia of the Fifth Army shows a Wyvern BattleMech scaling a cliff. Per FM: ComStar, page 28.