The Stealths use a dark blue-violet on the torso or hull, fading to black on limbs and turrets.
Canonized by Fanjoy on 8-1-2015.

Many enemies believe the Stealths forego using a unit insignia, when in fact they do use one. It is simply painted on their BattleMech torsos and vehicle bodies in UV ink, only visible under a blacklight, on the dark blue-violet paint scheme. – per Turning Points: Tyrfing, pg. 11