Monster Brains has released a full scan of The Official Advanced Dungeons & Dragons Coloring Album. Illustrated by Greg Irons (deceased, 1984) it was originally published in 1979 and is currently out of print. From the Monster Brains blog:
I’ve chosen to share the entire coloring book for anyone interested in printing it out and coloring it themselves. Every page is included in order. I don’t normally share copyrighted material in its entirety, however considering this “coloring book” has been out of print for over 30 years, I feel this thing deserves to be shared. If copyright holders of this book are opposed to my sharing it, feel free to contact me and I’ll remove it by request.