NightMare Moon was taking over all of Equestria, no pony had control as Celestia fought to maintain order and balance, as hards as she might, she was losing. With a heavy heart she had formulated a plan, but said plan had such flaws, the elements of harmony required more than one pony to wield them, if she wield them herself, who knows what will happen, she might not have the strength to lift the sun! she would have made a solution but she was far too busy trying to fend of Nightmare Moon and her minions of Night Dwellers, so as a last resort, she had left the plans to her followers, the Pegasi, Unicorn, and Earth ponies alike, hoping they would help aid this part of the war.

Author's Note

I do not own the Rainbow factory (as awesome that would be but AuroraDawn owns it :P) but this is simply my take on how the rainbow factory began which case i'd love it if you argued against my theory of how this all went down but in any case hope you enjoy :3