Mercury Black/Behind the Scenes

Throughout the production of a series, a lot goes on behind the scenes in regards to planning and design, which often go through multiple stages before resulting in the final version that is seen on screen. Some concepts and ideas can have an effect on the show and characters, and unexpected occurrences during production can also lead to changes and additions to the plans for the show.

Character Basis
Mercury Black alludes to the mythological figure Mercury, who is the Roman equivalent to Hermes. This allusion has had the following influences on the character and show:
 * His first name is Mercury.
 * His emblem resembles a boot with wings on it. The Roman god Mercury is often depicted wearing a pair of sandals with wings on them.
 * His weapons are worn on his feet.

Emblem
Mercury's emblem is a boot with wings on it. This emblem appears on one of Mercury's possessions:
 * Battle outfit - the fabric worn at his hip

Battle Outfit
Mercury makes his first appearance in the Volume 1 after credits scene as a 2D image, wearing an outfit that differs from the final version worn by his 3D model. The scene is very dark, but with a little editing, his outfit becomes more visible. The 2D version's differences are
 * The collar of his jacket is completely zipped up
 * The short sleeves of his jacket are completely gray
 * He is wearing a pair of crossed belts
 * He lacks the piece of fabric hanging from his hip
 * He is not wearing gloves

Later concept art features four outfits and a different hairstyle. Like his final design, these outfits have jackets with black designs and armor on his arms. Unlike his final design, all four outfits have the jacket's collar zipped the way up and lack a piece of fabric hanging from his hip.

The first design's hair is mostly slicked back, with wavy bangs hanging in front of his right eye. The outfit bears the same gray and black color scheme as his final design, but it has the following differences:
 * The jacket has no sleeves instead of short sleeves
 * He is wearing a gray belt with a black belt buckle
 * The pants are gray on the inner thighs
 * The armor covers his shoulders
 * He is not wearing gloves

The second outfit bears the following differences from the final design:
 * The jacket has no sleeves
 * The jacket is black and white
 * The black coloring has a different pattern
 * He is wearing a white belt
 * He is not wearing gloves

The third outfit bears the following differences from the final design:
 * The jacket has no sleeves
 * The jacket is black and yellow
 * The black coloring on the jacket has a different pattern
 * The pants are black and white
 * The armor covers his shoulders and collar bone
 * He is not wearing a belt
 * He is not wearing gloves

The fourth outfit more closely resembles his final design, with the following differences:
 * The armor covers less of his arms
 * The pants are black and white
 * He is not wearing a belt

In Volume 4, Mercury no longer wears a piece of fabric on his hip.

Concepts With No Change
There is no visible difference between the concept art and final versions of the following appearance.

Production

 * Mercury first appears as a 2D drawing in the Volume 1 after credits scene because he did not yet have a model. He makes his first appearance as a 3D model in "Best Day Ever".
 * In Volume 2, Mercury is voiced by J.J. Castillo. Between Volumes 2 and 3, J.J. left Rooster Teeth and did not continue voice acting for RWBY. From Volume 3 onward, Mercury is voiced by Yuri Lowenthal.
 * After Volume 3, Rooster Teeth changed animation software from Poser Pro 2013 to Autodesk Maya. With this change, the animation department also made all new models for RWBY. The Mercury Black model's eyes were given a different shape.