the one with the green is a witch and the one with the red is a wizard. they need names!! So, the wizard focuses mainly on demonic activity and stuff like that. so, one day, she makes a deal with a demon to have a child in exchange for something. idk what. then, she makes a deal with a witch to give here her first born child. the witch hangs with her and makes sure the pregnancy goes smoothly and they fall in love. they move around a lot so the demon can't corrupt Cressida. also, the reason that the witch's hair is purple. so, you know how both collie and ca have white hair with purple? so, for that certain type of witch, the more magic the use, the more purple their hair grows. collie also practices wizard magic though, so that doesn't turn their hair purple. basically, the witch here has used a lot of magic. ace hasn't used much magic, so they have almost no purple streaks. Lucas is a more dark magic focused witch, so he has darker hair. (dark magic isn't bad) also, some wizards, depending on their magic, also have the white to purple hair change, like Gwen. it's a specific type of magic.