The story of Siri and Viviena is well illustrated, thougtful and educational. The premise of Color Magic, Returned Gods and sacrificing the virginity of a 17 year old to a god are good material.
Unfortunately this book seems to be written for 14 year olds. First, for those affllicted with attention deficits, every idea and little twist in the plot is chewed over and over: first hinted at in one scene, then confirmed in another and finally explained through the thoughts and discourses of the protagonists. Second, contrary to the premise, everybody in this book is so overly moral - including the bad guys. Finally the description is repetitive. I don't want to hear that someone "raised an eyebrow" ever again.
Now if these kinds of things don't bother you - go ahead, listen to it you'll have fun. I just didn't like it because I'm not 14 anymore and I don't see any reason to go for mediocrity.