Chromatic and Metallic Dragons

The first dragons were all chromatic dragons. Birthed from the shattered mind of the already unstable Keryth, they were a destructive and dangerous new element to the Material Plane.
But they were also fragments of Keryth, who the other gods pitied for her fate, and they were loath to simply destroy or lock away these remnants of herself. So instead the forge gods gathered as many dragons as they could find, and in the fires of their forges, the two sought to remake the dragons into a form more pleasing and less destructive. They created the first metallic dragons, and the artifacts needed to make them. After the initial challenge, these artifacts made the process quick and easy.
This was met with a mixed response. Many of the gods, and a few of the dragons, met this discovery with relief and joy. But many of the remaining chromatic dragons did not want their bodies and minds reshaped to be virtually unrecognizable, and they fled. The gods hunted them, until a voice whispered in their minds, guiding a brave group of nine chromatic dragons--one of each color--to sneak into the forge of the gods and steal the Dragonforging Artifacts. Using the power in these artifacts and their new, dragon-specific arcane magic, they locked the gods out of the Material Plane, limiting their ability to interfere directly and forcing them to work through their servants exclusively. And thus, the gods no longer walked the earth.