In chapter 7, Nigel Blackheart describes Chris' Kira costume as such:
'The screen suddenly changes to show what i can only assume is Kira, although his costume exposes not a centimetre of the man himself. The costume seems to consist of a tight dark purple suit, with golden stripes and long, wrapped sleeves. Worn over it is a black and gold cloak with a crimson material lining the inside and an enormous black cape encircling the head, the inside of which seems to be glowing bright red. His cloak seems to be covering something on his suit around wait level, but I can't see what it is. But one of the most visible parts of the entire costume is a spiky black and red helmet, completely hiding Kira's face. Aside from that, a black stylized K is imprinted on his otherwise-white collar. Behind Kira, a large flag covers the entire background, with a white stylized K on a black, featureless background.'
Chris' Kira costume was originally a cosplay for Lelouch vi Britannia from Code Geass, which was quickly modified with the addition of the glowing red material covering the cape, the red one-way glass visor, the K symbol on the collar, the southern cross and other minor changes.