Monochrome Superheroes?

This is the first book in the Icarus Project Series by Jackie Kessler & Caitlin Kittredge.
In this worlds the Extrahumans(people with extraordinary superpowers) and the normal population live besides each other with more or less acceptance on both sides. It's all about the definition of Good and Bad, Black and White, Ying and Yang. Is there always a straight line deviding them or can you be caught in the middle. Which one is the Good site and who's Bad?

"Black and White" by Jackie Kessler & Caitlin Kittredge

Description:
Once best friends at an elite superhero training academy, Callie
Bradford--code name Iridium--and Joannie Greene--code name Jet--are now
mortal enemies. Jet is a by-the-book hero, using her Shadow power to protect
the citizens of New Chicago. Iridium, with her mastery of Light, runs the
city's underworld. For years the two have played a dangerous game of cat and mouse.
But now playtime's over. A looming evil threatens both them and the world
they share. As Jet works with a "normal" man who has an extraordinary
ability to make her weak in the knees, Iridium teams with a mysterious
vigilante called Taser. Both Jet and Iridium are convinced that the other
woman is the key to a catastrophe of apocalyptic proportions.
And one of them is right. (by goodreads.com)

Review:
Before I read this book I couldn't imagine how great a book written by two authors can be. I love the way they split the story between Jet and Iridium. In the beginning it's a little confusing to read the story from two points of view, but it makes the whole story more exciting and fascinating. I also love the way they reveal the history of both heroines along the storyline. It keeps you in the dark and you want to now what happened to them. I was unable to put the book away. Just brilliant.