The colors of the Iron Hand are red with green accents.
Per FM:Periphery, page 30.
Thunder, FM: Periphery (color plate 2)
Phoenix Hawk, Field Manual: Updates (cover)
The insignia of the Magistracy Royal Guards is an Amazon warrior trampling a snake. Their insignia is a red, right-hand gauntlet held palm out with the world of Canopus IV on its palm. Per FM:Periphery, pages 26 and 30.