Funny you post this, I'm just finishing reading this book from a library copy. The narrative in the book is probably the most fascinating part. The dialog from Adams in the book mainly explains his frustration with print technology and trying to represent a scene in color as being 'realistic'. I really found this a bit odd because Ansel always stated that his B&W masterpieces weren't about representing a scene in a realistic fashion.
None the less, the book is well done. The images are rescanned and updated for current print technologies. Few of the images would I put anywhere in the same classification as Ansel's B&W work. These color images were mostly 'commercial' work done for Kodak during the 1940s and 1950s. A few examples from the 1960s and 70s.
The basis for the book is an outline Ansel was working on prior to his death. He had laid out an outline for a book on his color photography. This recent release is the most extensive presentation of color works by Ansel Adams.
On a personal note, I enjoyed the book, but don't plan on buying it. The story, not the images are what fascinated me. I find the work of Eliot Porter to be much more artistic and rewarding from a visual standpoint. Ansel makes reference to the work Eliot Porter was doing in the same time period.
It is note worthy that Eliot Porter was a dedicated nature photographer based in color. As far as my research has found, he is the grand father of color nature photography. Some of his bird images are stunning, then when you consider he was doing bird flight photography as early as the 1940s, it is remarkable work. I have several of the gorgeous books Porter did and find them all very enjoyable.
These examples of color work by Ansel are worth exploring to get a broader picture of his photography eye and ability.
Ansel Adams in Color at Barnes and Noble