Armor Permutations

Halo 3 Armor Permutations
Helmet

Mark VI: Default

CQB: Default

EVA: Campaign Complete: Normal

EOD: Campaign Complete: Legendary

Hayabusa: Collect all 13 skulls

Security: Get 1,000 Gamerscore

Recon: Complete the Vidmaster Challenges

Scout: Earn the Used Car Salesman Achievement

ODST: Become a Spartan Graduate

Mark V: Become a UNSC Spartan

Rogue: Become a Spartan Officer

Combat: Default

Assault: Default

Flight: Campaign Complete: Heroic

Ascetic: Earn the Steppin' Razor Achievement

Commando: Earn the Overkill Achievement

Shoulder

Mark VI: Default

CQB: Default

EVA: Beat The Ark on Normal

EOD: Beat The Ark on Legendary

Hayabusa: Collect 9 Skulls

Security: Get 750 Gamerscore

Recon: Complete the Vidmaster Challenges

Scout: Earn the Mongoose Mowdown Achievement

Combat: Default

Assault: Default

Flight: Beat The Ark on Heroic

Ascetic: Get the medal Overkill

Commando: Steppin' Razor

Body

Mark VI: Default

CQB: Default

EVA: Beat Tsavo Highway on Normal

EOD: Beat Tsavo Highway on Legendary

Hayabusa: Collect 5 Skulls

Katana: Earn 49 Achievements and get 1,000 Gamerscore

Bungie: Bungie Employees only

Recon: Complete the Vidmaster Challenges

Scout: Earn the Too Close To The Sun Achievement

Combat: Default

Assault: Default

Flight: Beat Tsavo Highway on Heroic

Ascetic: Earn the Up Close And Personal Achievement

Commando: Earn the Triple Kill Achievement

Halo 3: ODST Armor Permutations
Rookie: Default

Sgt. Johnson: Pre-order Halo 3: ODST

Dare: Campaign Complete: Legendary

Buck: Earn the Tayari Plaza Achievement

Dutch: Earn the Uplift Reserve Achievement

Romeo: Earn the NMPD HQ Achievement

Mickey: Earn the Kizingo Boulevard Achievement