Brent Weeks showed the SF/F world what he could do with his first books, the Night Angel trilogy. In The Black Prism, he keeps up that high standard. Prism is a different world than Night Angel, with a different magic system, and a whole different cast of characters and personalities.
Prism gives us the Chromeria - a conservative, possibly corrupt guild governing 'drafters' - people who draw on light and color to produce magic. The Chromeria is led by Gavin Guile, the mysterious Prism, who can handle all seven colors at once. We follow both Guile and Kip, the young, obese boy from a devastated town who is, of course, destined for greater things.
The writing this time is not as smooth as it was with Night Angel, suggesting a greater rush to get the books out, and less consistent editing. There are places where the prose could have been tweaked for greater effect. More important, there are several gaps or not-credible coincidences in the story that have been thinly papered over, or not at all. Not enough to seriously set the reader back, but where you wish there had been even a paragraph or two of hand waving.
All in all, a very fun read, and well worth picking up - either for Weeks fans, or for newcomers who enjoy epic fantasy.