I've decided to stick with black text on white background for the following reasons:
1. We will likely still have a fair amount of black & white art and maps in the books (just as The One Ring does, for instance). By sticking with a white page, we make that cleaner.
2. Black text on white background is much easier to print on at-home printers.
3. Black text on white background is somewhat easier to read and I'm getting old and need glasses.
4. We're old school.
Therefore all of these selections use black text on white background, but with example and table boxes in parchment background. Variants involve the presentation of the example and table boxes with borders, scrolling, and shading. Let me know what you think!