A bit of news... The printed versions for the Math Mammoth Blue series books are now available in FULL COLOR. 😃 They're available through Lulu.com, as before, and printed on-demand. To find these, first locate the books you're interested in the list of Blue series books at MathMammoth.com . Then, for each book, you will find a link to Lulu listed under the cover image of that book. Check out also https://www.lulu.com/ home page for coupon codes; they run promotions often!