Avatars currently come in 3 rarity types and 4 professions.
Common — Cadet blue
A blue background signifies a rank of Cadet. Cadets are the most common rank, and they make up approximately 89% of all Martians. They are tasked with building out the colonies, and are granted more patience than higher ranks as they learn Martian Ethics.
Rare — Explorer purple
A purple background signifies a rank of Explorer. About 10% of Martians are explorers, and they are tasked with exploration and innovation. They are proven Martians helping to create or find solutions, and are expected to have internalized Martian Ethics and live fairly. "Explorers" is both a rank in the Martian Command (MC) system as well as what avatar-users are called.
Legendary — Atlas red
A red background signifies a rank of Atlas. At only about 1% of the Martian population, Atlas-ranking Martians are de facto legends in the Colony. Just as the titan Atlas held the Earth on its shoulders in mythology, Atlas Martians have dedicated themselves to serving all Martians. They are expected to display Martian Ethics with their lives, and lead by example.