I just checked out two large hardcover books from the local library devoted to Porter. His color imagery is amazing. The use of color is integral to the development of the overall composition. This explains at least to me at least why I found his B&W stuff so uninteresting.
It's funny how AA found it hard to cross over to color and how someone like Porter can not really carry off his imagery in B&W. At least IMHO anyway.
What are your thoughts on Porter?