I have nothing against color. In fact, I want my *next* challenge to be a color book, either watercolor, or a spot color book. But this was the style I settled on for this particular set of illustrations, and I think the mind's eye is better in this case.
Believe me, I thought about it. But then I realized a lot of my favorite illustrators use black and white or at best a subtle use of color, and then I stopped worrying about it and just finished the book.
And as much as I would like to afford it, color for an art print, a la Hokusai or Hiroshima would be too expensive. Maybe someday I'll make a super-deluxe woodblock print version of this book like that — which would be pretty awesome.