These days we get colouring books for both adults and childres.

Colouring books for children teaches motor skills, improves hand strength and dexterity.

Colouring Books for adults are a form of therapy that have seen a growth in popularity in the 2010s. They reportedly bring people a sense of their childhood, and help with  reducing anxiety and creating focus, and relieving stress and anxiety in a manner similar to meditation.  And it is great fun.