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

Per FM: ComStar, page 17.

Other references:
Rifleman, Battle of Tukayyid (p 165)
Sentinel, Battle of Tukayyid (p 178)


Insignia:

The insignia of the Second Army is a Black Knight-class BattleMech, its right arm raised in a salute. Per FM: ComStar, page 22.