GL is in the current DC main event. And green isn't the only color (and corresponding energy) with an oath:
Green (Willpower):
In Brightest Day,
In Blackest Night,
No Evil shall escape my sight.
Let those who worship Evil's might,
Beware my Power,
Green Lantern's Light!
Yellow (Fear) [Sinestro Corps]:
In blackest day, in brightest night,
Beware your fears made into light
Let those who try to stop what's right,
Burn like my power ... Sinestro's might!
Violet (Love) [Star Sapphires]:
For hearts long lost and full of fright,
For those alone in blackest night,
Accept our ring and join our fight,
Love conquers all-- With violet light!
Red (Rage):
With blood and rage of crimson red,
Ripped from a corpse so freshly dead,
Together with our hellish hate,
We'll burn you all--That is your fate!
Blue (Hope):
In fearful day, in raging night,
With strong hearts full, our souls ignite,
When all seems lost in the War of Light,
Look to the stars-- For hope burns bright!
Indigo (Compassion):
Tor lorek san, bor nakka mur,
Natromo faan tornek wot ur,
Ter lantern ker lo Abin Sur,
Taan lek lek nok -- Formorrow Sur!
(untranslated)
Orange (Greed):
'No oath, because only one... and he don't want to share!'
Black (Death):
The Blackest Night falls from the skies,
The darkness grows as all light dies,
We crave your hearts and your demise,
By my black hand--The dead shall rise!
White (Life/Destiny):
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