The Indigo Revolution was a core part to Lunas road to unification. It started with rumors of a Vault having survived the destruction of Earth, wich contained untold riches, like preserved plant and animals knowledge and human artifacts. This rumor started goldrush like surge of activity within the Grave, especially from various factions borth from Luna and the rest of human space.
A faction on Luna clad in indigo was one of the most vocal protesters, and managed to align Lunas various divided domes, countries and habitats into a single focus. In a swift but violent attack, the greedy and now unremembered factions on Luna was destroyed. And the Luna pepole sat out to blocade the Grave. War was declared, and the dwarf planet Ceres that was owned by the Megacorps Ceres Prospectors United for decades was annexed, whos fleet had managed to find the vault. The now United lunarian fleets fired on all who tried to enter the Grave. And eventually things calmed down. In record time over a solar year, all the foreign debris of ships where removed from the Grave and the asteroid containing the Vault returned to its original location. It is rumored that the Vault is now empty, and its content is now well guarded deep bellow Lunas Surface by the Lunarian Government.