The Principes’ color scheme is white with gold accents.
Per Field Manual: 3085, p.181
Lament, ilClan (p 64)
The Guards’ insignia shows the profile of Athena, Greek goddess of civilization, community and warfare, set against a gold disk. As with the other line brigades, the Principes Guards indicate their home Prefecture with a superscripted Arabic numeral to the right of their brigade insignia and their particular regiment designation with a subscripted numeral to the left. Per Field Manual: 3085, p.180