After the white elephants and the black elephants kill each other off, the grey decendants of those nonfighting elephants who hid during the war emerge only to find new differences to set them against each other.
Once elephants came in two colours: black or white. They loved all other creatures – but each set wanted to exterminate the elephants that were not the same as themselves. Peace-loving individuals ran and hid in the deepest jungle, and battle commenced. The war-mongers all succeeded. For a long time it seemed that there were no elephants in the world at all, not of any colour. But then the descendants of the peace-loving ones emerged from the jungle, and by now they were all grey.