The publishing company wanted to commission Basford for a traditional children's book in 2011, but she had other ideas — though she said the editors took some convincing.

"For years people have been telling me that they would like to color my monochrome creations, so I pitched them a coloring book for grown ups," she told BuzzFeed News. "At that time coloring for adults wasn't the global trend that it is now, so they were understandably a bit skeptical."