The Com Guards simply paint their vehicles white for official occasions and use appropriate camouflage for combat.
Per FM: ComStar, page 17.
Shadow Hawk, Battle of Tukayyid (p 163)
Sentinel, Battle of Tukayyid (p 178)
The insignia of the Eighth Army shows a gargoyle perched on the shoulder of a Guillotine BattleMech. Per FM: ComStar, page 34.