Excerpt from the Siren Star setting:
Following the War, the Human race was divided. The core worlds in the Revati sector surrounding Daykia prime belong to the xenophobic Republic. On the other side of the split lies the Confederacy: a gathering of colonies united to the common cause of survival in a hostile galaxy. Taking name after the world where the constitutional treaty was signed, and the founding council remains, these frontiersmen and colonists call themselves the Doelmyrran. Many Doelmyrran humans have developed cosmetic differences to their Daykian kin. Examples include skin pigmentation, eye and hair colors and the like – in the generations passed since they left their ancestral home. While these changes don’t make them any less human, it is enough for them to be labeled nonhuman by the xenophobic Republic.