Probably not, unfortunately—there's a lot of overlapping intersecting layers of InDesign and Photoshop going on to get the complete PDF that makes a simple black-and-white version difficult to produce.
I agree that the selected font is a huge accessibility issue between pages 30-48 (the dark brown text on lighter brown background), even on digital. How about a PDF version were the only thing that changes is making the font in those pages white or even match the more yellow tone of the text in page 50? Would that be possible? I love this adventure module and I can't wait to run it, but I've had a hard time reading those pages without ending up with a migraine.