The 11th adopted a color scheme of pure white with scarlet accents.
Per FM:Draconis Combine, page 37.
The Avengers insignia is a red dagger pointing out of an eclipsed sun with a flaming corona. This insignia appears on the upper right arm of all Alshain BattleMechs and is prominently displayed on all other vehicles. Per FM: Draconis Combine, page 35.