Did you get the print version from amazon? Or a bookstore? I've found the amazon print-on-demand quality to be stuck in "economode" sometimes. I personally recommend people to purchase from lulu because the print quality there is more consistent, though they too make mistakes sometimes.

Send me an email if the greyness bothers you—I'll be happy to send you a replacement copy from lulu, say when v6 comes out (no major changes; just more exercises because some people complained the onboarding was too hard for beginners).