The Imperial Castellans primarily wear cerulean blue coloured Power Armour, which includes the power pack, helmet, shoulder pads, torso and groin. The shoulder pad trim, arms and legs are tan in colour. The black coloured squad specialty symbol -- (Tactical, Assault, Devastator, or Veteran) -- is displayed on the right shoulder plate. A white-coloured Gothic numeral centred on the squad specialty symbol indicates squad number. The colour of the Aquila or Imperialis on the chest plate plate indicates company designation in accordance with the Codex Astartes -- i.e. White (1st Company), Yellow (2nd Company), Red (3rd Company) etc.