They're the colours of contentment, apparently. The adult colouring-in craze is booming in New Zealand, as bookstores give prime position to colouring books aimed at those far beyond primary school.
Whitcoulls head of books Joan Mackenzie said demand began four months ago and was "extraordinary".
"It caught on so quickly the publisher of the most preferred author, Johanna Basford, couldn't get enough paper [to meet demand]. We had waiting lists in the hundreds."
Gore grandmother Joyce Hurley is in her early 50s and is among the converts. She has been colouring in each night for a couple of months.
The florist has also hooked in her 75-year-old mother and 29-year-old daughter, who recently hosted a colouring-in party for her friends, and runs a 250-member Facebook page.
Sleeping troubles disappeared after she started colouring in, Hurley said. "It really relaxes you. I can't believe how dozy it makes me."
Victoria University associate professor of psychology Marc Wilson said the books were marketed as mindfulness tools and there was evidence well-structured mindfulness was useful in many situations. Research had also shown colouring geometric patterns reduced anxiety.
"These things will help quiet the raging mind, and it appears that something suitably detailed will do the trick as well."
Paper Plus group marketing manager Lyle Hastings described sales trends for adult colouring books over the past year as "nothing short of amazing", with a mind-boggling 36,000 per cent increase on popular titles.
In the past two weeks, nine of the top-20 bestsellers in New Zealand were adult colouring books. Fishpond general manager Ben Powles said sales of adult colouring-in books from the online retailer had increased from fewer than 100 in February to more than 500 in July. There were already 250 pre-orders for a Game of Thrones colouring book due out next month.
Golden Bay artist Sara Macready has just published her first adult colouring-in book, titled A Golden Bay Colouring Book.
"The sharing of [art] is what's important, getting people interested. We usually live in a little bubble as artists. I don't want to be part of this elitist thing at all."