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

Per FM: ComStar, page 17.

Other references:
Highlander, Black Knight, Exterminator, Crab, Battle of Tukayyid (front cover)
Black Knight, Battle of Tukayyid (p 171)
King Crab, Battle of Tukayyid (p 178)


Insignia:

The insignia of the Sixth Army shows an armored knight, standing with a sword in one hand and a mace in the other. Per FM: ComStar, page 30.