Live to Fight Another Day
The Grinders paint their machines in greens commonly seen on Liao units, accented by Capellan insignia.
Per Mercenaries Supplemental 2, page 35.
Firestarter Omni, Mercenaries Supplemental 2 (color plates)
The Grinders' insignia is a BattleMech's foot crushing an hourglass into the ground. Per FM: Mercenaries Supplemental II, page 35.