William revealed what Kate gets up to at home to Johanna Basford who picked up an OBE for services to art and entrepreneurship.
Adult colouring books – referred to as “colour therapy” – are hugely popular among those looking at new ways to unwind.
Ms Basford, 33, said: “I think we’ve just seen the colouring community flourish.
“And Prince William actually said that his wife likes to colour in the Secret Garden, which was really sweet.”
Secret Garden – a colouring book for adults – is Ms Basford’s first book and has sold more than 1 million copies.
Reflecting on the popularity of the craze, she said: “I think people are just craving a digital detox.”
In an unusual event, Ms Basford was joined at Buckingham Palace by her husband James Watt, co-owner of BrewDog, who collected an MBE for services to brewing.
Ms Blasford, joking about Kate and William’s potential interests, said: “So maybe she’s a fan of my work and he’s a fan of my husband’s.”
Meanwhile soul sensation Ruby Turner picked up an MBE after 40 years at the top of the music business.
British-Jamaican singer Turner, 58, has worked with legends like The Four Tops, The Temptations, Jimmy Ruffin and Culture Club.
Her instantly recognisable voice has also appeared on tracks by Brian Ferry, UB40, Steve Winwood and Sir Mick Jagger, and she is currently one of the main singers in Jools Holland’s R&B Orchestra. Yesterday <> Holland, 57, was her guest of honour as she received her gong.
The Duke of Cambridge also came face to face with a key aide, private secretary Miguel Head, who was made a Lieutenant of the Royal Victorian Order.
Leon Smith, captain of Britain’s Davis Cup tennis team, collected an OBE and said afterwards that William told him Kate screams at the TV when he and his team-mates are playing.
Surgeon Commander Matthew Turner received an OBE for his work leading a medical team dealing with migrant activity in the Agean Sea while Welsh Rugby Union president Dennis Gethin picked up an OBE for services to the sport.