Cut Halo 4 customization

Following in the footsteps of Halo: Reach, Halo 4 featured a large variety of player customization options, some of which hit the cutting room floor.

CIO
The CIO armor of Halo 4 featured multiple released skins, one of which was "Ruin", released with Series 2 of McFarlane's Halo 4 line of figures. The concept art of "Ruin" shows the armor's skin was originally present on its wrists and legs, but the skin's final release only features the skin on the armor's helmet, chest, and shoulders.

Gungnir
The Gungnir armor set's renders show the armor possessing unique wrist armor that would not be seen in the final release of Halo 4. While it would not appear in Halo 4, the armor's Halo 5: Guardians incarnation would feature it, as would Halo Online, and later, Halo 3's variant of the armor, dubbed COS-class Mjolnir.

Hayabusa
The Hayabusa armor, originally debuted as a crossover armor set in Halo 3, was concepted and modelled for inclusion in Halo 4 though ultimately never realized. This may be due to rights issues, as the original Hayabusa design was created as a crossover with Dead or Alive 4's Nicole-458 character.

Infiltrator
The Infiltrator armor was implemented in the final game, though some in-progress renders showcase a unique forearm design for the Infiltrator set not used in the final Halo 4 release. These wrists would later go on to be used in Halo 5: Guardians and Halo Online, and the Online armour port to Halo 3.

Locus
The base Locus helmet was originally accompanied by a variant with an alternate skin. Instead of an X-shaped pattern adorning the helmet's skull-like face, a basic stripe ran down this variant's face. This skin wasn't just exclusive to renders done by Liquid Development, and could be seen in officially released screenshots, although it remains unobtainable in both Halo 4, and Halo: The Master Chief Collection.

Mark IV
As seen in Awakening: The Art of Halo 4, the Mark IV armor set was concepted for inclusion in Halo 4. For unknown reasons, it was never fully realized, although it'd later make its debut in Halo 5: Guardians during the Cartographer's Gift update.

Recon
Liquid Development renders for Recon show the armor set was meant to get a unique set of leg armor, which was modelled fully. This unique permutation would be seen in Spartan Ops, with Anthony Madsen wearing it, but would remain unobtainable to players. While the armor would not appear in Halo 4, the armor's Halo 5: Guardians incarnation would feature this unique leg armor.

Soldier
Renders seen for the Soldier armor set in Halo 4 show the set featuring unique wrist and leg armor. These unique permutations would be seen in Spartan Ops, with Paul DeMarco wearing them, but remain unobtainable to players in-game. While the armor would not appear in Halo 4, the armor's Halo 5: Guardians incarnation would feature it, as would Halo Online, and later, Halo 3's variant of the armor.

Protector
The Protector armor was implemented in the final game, though some in-progress renders showcase a unique leg design for the Protector set not used in the final Halo 4 release. These legs would later go on to be used in Halo 5: Guardians.

Cut skins
In addition to cut armour options, Halo 4 had a large number of weapon skins that went unused in the original launch. Two such skins; Concrete (DMR) and Blast (BR), were present in the files of the original Halo 4 Xbox 360 release, introduced in the 8/19/2013 Title Update though unusable in-game outside of a glitch in custom games, and modding. These two skins were introduced into the Halo 4 component of Halo: The Master Chief Collection with the game's release on PC platforms in Series 4: Reclaimer and Series 7: Elite for Blast and Concrete, respectively.

Halo: The Master Chief Collection skins
In addition to the skins above, a number of additional never-before skins were introduced to The Master Chief Collection in Seasons 4 and 7, respectively - presumably additional cutting room floor skin variants that never saw the light of day in the original release.

Unused skin variants
These skins are unused variants of those which made appearances in the final releases of Halo 4, or The Master Chief Collection.