The Raiders use a dark red color scheme with black striping.
Per FM: Merc (revised), page 96.
Other references:
Atlas, CM: Mercenaries (p 110)
The unit insignia is a pirate riding atop a Leopard-class Dropship; it is painted on the torsos of the unit’s BattleMechs and the fuselages of its aerospace fighters. Per FM:Mercenaries Revised, page 96.
