Fireborn, by Toby Forward (Bloomsbury, 2013, upper Middle Grade/YA): it was very good, and I'm glad to have read it. It was a struggle to read it, and I had to keep putting it down.
It is the story of three kids--Beatrice and Cabbage, who both have magical abilities, and Perry, who is a roffle--a not-exactly-human denizen of a mysterious underworld. When magic goes terrible wrong due to the schemings of a truly nasty, second-rate magician, these three kids have to face the vicious consequences of the eruption of power that follows. And it is truly vicious--the magician and his companion are transformed into creatures of horror who kill, rather terribly, scores of people, and worse than that (in my maternal mind), Beatrice is left horribly, horribly, burned and disfigured. The adults looking after these kids do their best to handle things, but they are not able to defeat the enemy. Since Beatrice was there at the beginning of the wild magic, and caught in its birthfire, it is, in the end, up to her to find her way out of her pain into a place where she can use her birthright.
(If you want a somewhat more detailed, lyrical description, this would be a good point at which to read Kirkus' starred review).
Though much of the story distressed me (causing me to put the book down for little breaks), it is not all dolorous. Cabbage and Perry have a lovely friendship and are both tremendously endearing, and the adults (who aren't the bad guys) are actually good, kind, wise people, which is rather a rare thing, and which I enjoyed. I have decided that I like books in which the characters Talk to each other, and treat each other as people, and there is lots of good talking here, that both advances the story without tedious explication, and advances the reader's appreciation of the characters. The worldbuilding is solid, without bending over backward to explain every single detail--the reader has to take some things on trust, and it works (for instance, I still don't know what exactly the roffles are, but no one who isn't a roffle really does, so that's fine).
Fireborn is the prequel to Dragonborn (2012 in the US), and you should most definitely read this one first. In my review of Dragonborn, my main complaint was the absence of backstory--and that is what Fireborn delivers.
Bonus challenging of gender stereotypes regarding pink:
Young Cabbage is visiting the college of magic, and is waiting around in the office of the head of the school ( a woman). "I'll have a room like this one day, he decided. The light swam in through one of the high, broad windows. The walls were painted a delicate pink. It was a good pink, with a blush of rose. He liked pink. He wouldn't change the bookcases either." (page 195).
The school of magic, incidentally, has a lovely library.