Today there are nine colors of the Emotional Electromagnetic Spectrum, each bearing a unique color and emotion assigned to a particular energy field managed by a Lantern Corps. This summer, potentially as a result of the Source Wall breach in Dark Nights Metal, DC Comics will introduce a 10th spectrum: Ultraviolet light.
Who will be wielding this new portion of the Spectrum? None other than current Green Lantern John Stewart. Check out the cover art (below) by Jorge Jiménez showing Stewart sporting a new ring and the Ultraviolet logo. Jim Lee and Scott Williams will provide a variant cover.
Solicited (via CBR) in the upcoming pages of Justice League #3 and #4 for July 4 and 18, respectively, Scott Snyder and Jiménez will tell a tale that will feature Stewart harnessing ultraviolence and unleashing it against his fellow big hitter Justice League teammates Flash, Wonder Woman, and Aquaman. In Issue #3, "the rest of the League investigates the scene of the fallen Source Wall fragment, and encounters not only a horde of giant monsters, but a pair of longtime archenemies using stolen Atom technology to literally get under their skin," according to DC.
Issue #4 expands the ultraviolet arc: "What is hidden in the darkest depths of the ocean and farthest reaches of space doesn’t even compare to the insidious secrets buried in the pasts of Flash, Green Lantern, and Martian Manhunter! While the rest of the League battles to save their friends before all of reality unravels, the citizens of Earth make a startling decision… to join the Legion of Doom!"
No telling yet if Stewart will be the first of many Ultraviolet Lanterns, or if he'll lead a team on his own. But he is the first to wield this new power, and expect him to be in this ultraviolent state for a bit. With the realm of the Dark Multiverse, there could be new areas and sectors for the Lanterns to monitor over. We'll have to see if the Guardians of Oa determine John needs to be reassigned, and what the story is surrounding this new ring.
The most commonly known Lantern Corps is the Green, represented by willpower and used by the Oans who are the Guardians of the Universe as a power to combat evil in the universe. When Geoff Johns wrote Green Lantern: Rebirth, he introduced the rest of Spectrum, including Red Lanterns, representing anger and rage; Yellow (long used by Sinestro), representing fear; Orange, representing avarice and greed; Blue, representing Hope; Indigo, representing compassion; and finally Violet, representing love.
While not technically part of the Emotional spectrum, there are two other light-based classifications: Black, representing the color of death, and White Lanterns, representing Life, where the Emotional Electromagnetic Spectrum originated.