Real Names: Unpronounceable
The Still Zone, first as their fortress, then later as a Justice League run prison.
Red in their natural form
Chalk White in their natural form
White Vs. Green Martians
Eons ago the Evil Pale or "White Martians" invaded Earth. Without really caring for Earth, the White Martians brought destruction to Earth's environment. Besides the White Martians there were also the Green Martians, a more peaceful race of martians. The White Martians rampage on Earth resulted in the slow down of superhuman evolution. Taking matters into their own hands the Green Martians imprisoned their counterparts in the Ghost Zone (also known as the Still Zone or Phantom Zone) for what they thought to be forever. But, eventually the White Martians came back. After the Justice League Of America defeated the White Martian's initial invasion, lead by the Hyperclan, the Martian Manhunter wiped them of all their previous memories making them think that were and had always been only human. In an encounter with the wish-granting Id, J'onn J'onnz (the Martian Manhunter) inadvertently bought back his fellow martians through a wish she granted him of wanting company.
Extricating themselves from the Still Zone aka Ghost Zone or Phantom Zone, the White Martians returned to Earth in the guise of gods calling themselves the Hyperclan. The Martians claimed their homeworld had been destroyed by negligence and greed and they offered to save Earth from a similar fate. The Hyperclan turned deserts into verdant paradises and ended crime by executing meta-criminals. This was all part of their insidious plan to discredit and destroy the Justice League. Earth's real heroes saw through this ruse and put a stop to it right away. All hope seemed lost after the White Martians took away the only means of defeating them, by burning them with fire. The Martians took this away from Earth by inhibiting the Earth's atmosphere with subatomic particles that inhibited any combustible reaction. To find a way around this the Justice Leagues lured the Martians to the Justice League Watchtower and the moon aflame.
After the events of the Obsidian Age, the Martian Manhunter sought out therapeutic help against his otherwise crippling fear of fire that affects all Martians. Mostly conquering this fear with the aid of the reforming criminal Scorch, J'onn however unlocked a personality buried within himself called Fernus, a personality that was only kept in check through the Martian's genetic fear of fire. Unknown to all, save the Guardians of the Universe, the Martian race had once been a single race, called the Burning. The Guardians feared the Burning, at the time limited to Mars, would achieve interstellar flight and spread beyond Mars and inflict the rest of the cosmos with their chaos, as the Burning could reproduce asexually as long as they could find a proper flame. The Guardians found it necessary to descend on Mars and the Burning, breaking the Martians down into two species resulting in the Green and the White Martians, and creating their great fear of fire to prevent their Burning mentality from returning, something they were unable to completely remove.
When J'onn finally lost himself inside Fernus, the White Martians held in the Still Zone were amongst the first to suffer his ire and as a result, they were all butchered before the League arrived.
Despite what Fernus did, it was not the end of the White Martian race. During the One Year Later gap, the Teen Titans recruited a young woman that looked very much like the Martian Manhunter called M'gann M'orzz. However, like many that year, Megan didn't remain for long due to the turmoil the team was in at the time. After Cyborg returned and woke up with the knowledge that Raven had uncovered a traitor during the year he was out and was now on the run, the team ventured to the Australian Outback to meet with Megan before being pointed at Bombshell after refusing to expose her mind to the world. However, after the Titans had left, she did anyway, and discovered that Bombshell was the traitor and headed after them. Initially there was confusion when Bombshell blasted Megan out of her Green Martian guise, revealing that she was in fact a White Martian. Because of the White Martians dire reputation the Titans initially thought Megan was the traitor, before being blindsided by Bombshell.
Megan has since then revealed that her parents had sent her into the Vegan system when she was an infant to shield her from the wars plaguing their people, but when she came back they were gone and she headed to Earth. It is only known that she has met J'onn in person once, during the Brightest Day story arc, when she was ambushed and nearly slain in her Outback retreat by the insane Green Martian called D'kay before J'onn arrived.
Pale/White Martian Powers & Abilities
White Martian abilities are similar to those of the Green Martians, and they they have numerous superhuman powers, including superhuman strength, flight, invisibility, telepathy, shape-changing, phase-shifting (sometimes called variable density) which allows them to be either invulnerably tough or completely immaterial, and "Martian vision" (a form of energy projection from their eyes), but they also share the Green Martians' vulnerability to fire.