The many faces of Rhia.

Okay, so, Rhia goes through quite a few changes and has a number of different 'personalities' that exist within herself. It's quite confusing just thinking about it, so hopefully I can explain it so that it's a little more understandable.

As mentioned before, Rhia's born half Drow, half Wood elf. Through this bloodline, she acquired both black magick and white magick.
When she was born, she appeared as a Drow: black or very dark gray skin, silver hair, red eyes; the only thing that wasn't Drow about her was the silver birthmark on her right shoulder - the Star of Elbereth, something only Wood elves of royal descent acquired. It was the same birthmark that gave her away, but that's a different story.
After Rhia was expelled from the colony, and shortly after she fled Tobias' kingdom, she came across a witch who heard Rhia's wish to be rid of her Drow qualities, which had gotten her in trouble in the first place. What she did about it was begin a seperation of Rhia's Drow blood from her Wood. However, the proceedure was interrupted, and the schizm wasn't complete, but that's also another story.
So, after a few hundred years, Rhia slowly changed appearance, as her Drow blood receeded into the personality (and person) of Kalvin. Her skin began to pale, going gray before getting a peach tone, though she always stayed a little gray. Her hair darkened and became brown (which is still a mystery even to me, as brown hair is not a quality of either Wood elves or Drow), though her eyes remained red.
After some extended period of time, not entirely sure of exactly how long just yet, Kalvin finally splits from Rhia.
Now, I'm not really certain yet if it will be before or after Kalvin splits from Rhia that Romeo brings personality to Rhia's magick. Either way, in order that they could govern Rhia's body without her having to worry about it, Romeo gave her magick personality, thus creating Arcane and White; it was a while yet before they gained a voice, and ultimately bodies when they were removed from her soul in order to give some breathing space for the last personality.
That personality being the Golden (or second, in my books) Angel of the Apocolypse. It's just as the civilizations in Armenia and Mesopotamia were going up that God sends these Angels to Earth (they'd always existed, which is an important aspect to a side story that will come later). Fatima, this particular angel, was placed inside the soul of Rhia, she chosen to be the one who walks the Earth for all her(Earth's) days. And, it's because of Fatima that Romeo was created, he sent to Earth to look after Rhia and make sure she wasn't killed.

That's really about it. There's a lot of detail about the relationships (not strictly romance, but the actual bonds and rules and what not) between each of these personalities, but that will be gone over either here later or in the books themselves.