All Horde armor is painted in a red desert camouflage pattern.
Per Mercenaries Supplemental 2, page 56.
Other references:
Elemental, Mercenaries Supplemental 2 (color plates)
The Horde’s insignia is a bull with red eyes and flaming nostrils, covered in black armored plates trimmed in silver.
Per FM: Mercenaries Supplemental II, page 56.
