The Illician Lancers use a typical color scheme of green, khaki and rust red when not in combat situations.

59th Strike Regiment adds distinctive yellow highlights
4th Illician Rangers adds distinctive blood red highlights
9th Illician Rangers adds blue highlights

Per Mercenaries Supplemental, pages 39-42.

Other references:
Cossack, Mercenaries Supplemental (color plates)
Grasshopper, CM: Mercenaries (p 108)
Regent, Dominions Divided (p 68)


Insignia:

The Lancer insignia is a yellow lightning bolt set upon a stylized bullet. The Fifty-Ninth Strike Regiment’s insignia is two lightning bolts crossed under an upward facing arrow, all set upon an orange disc. The Fourth Illician Rangers’ insignia is a sword and an arrow crossed over a lance, set upon the same stylized bullet as the Lancers’ insignia, with a “4th” set at the top. The Ninth Illician Rangers’ insignia is two lightning bolts set atop an arrow on the ground pointing toward a setting sun. The insignia for the Twenty-first Illician Rangers is a lightning bolt sundering a planet in half. Per FM: Mercenaries Supplemental, pages 39-43.