Lantern oaths. White, whose oath has not yet been spoken, represent life. Red is rage. Orange is avarice. Yellow, the Sinestro Corps, is fear. Green is willpower. Blue is hope. Indigo tribe (oath spoken and written in native tongue) is compassion. Star Sapphires wield love. Black represent death.
Hal Jordan is the greatest Green Lantern, an inter-galactic police officer and member of the Green Lantern Corps. The strength of his willpower allows him to wield the universe's mightiest weapon, a power ring controlled by his thoughts. In his secret identity he is a test pilot working for Ferris Aircraft where his boss Carol Ferris is also his romantic interest.