The War of Light is an all-out war fought by the Green Lantern Corps. Aside from the already existing Sinestro Corps, all other colors of the Emotional Electromagnetic Spectrum also possess a special Corps: the Star Sapphire Corps, the Red Lantern Corps, the Blue Lantern Corps, the Orange Lantern Corps, and the Indigo Lantern Corps. The war culminates in the Blackest Night, the darkest prophecy of the Book of Oa.
