The Masters of Proteus primarily wear white Power Armour. Parts of their battle-plate are blue, including the Aquila or Imperialis on the chest guard, the power pack, shoulder plate trim, both knee guards and both feet. The blue squad specialty symbol -- Tactical, Devastator, Assault or Veteran -- is located on the right shoulder plate. A white Roman numeral is stenciled in the centre of the squad specialty symbol, indicating squad number. The colour of the helmet stripe indicates company number in accordance with the Codex Astates -- i.e. White (1st Company), Yellow (2nd Company), Red (3rd Company), Green (4th Company), etc.
The Masters of Protelus' Chapter badge is a blue double-headed battle-axe on a field of white.
- Adeptus Astartes: Successor Chapters (Limited Released Booklet)
- Insignium Astartes: The Uniforms and Regalia of the Space Marines, pg. 57
- Space Marines: Collector's Guide, pg. 6