So how it works is that when a demon is born, their abilities and appearance are influenced by 2 things. Their parents and the ring they were born in. If the parents are from the same Ring, the child will be born to look like them. They will also inherit abilities from the ring they were born in a long with their parents. But if one of the parents is different, and is from a different ring, the childs appearance would change to look moreso like the a mix between both demons that conceived it. With it they also gain new abilities from the odd parent. How their ring influences their appearance is that they may become a color that's commonly found in that ring or a mixed color of that ring and the parents.