The Republican Guards use a quartered red and black paint scheme on all their equipment.  The first also uses gold highlights upon their ‘Mechs.
-Per CSO (edited 6/13/23) and FM: Lyran Alliance, page 105.

Other references:
none


Insignia:

The unit’s insignia is a torch set within a crown, atop a red triangular field. The First Republican’s insignia is a variation of the Republican Guard’s crest, with a sword replacing the torch. Per FM:Lyran Alliance, pages 104 and 105.