One of the first psychologists who in the early twentieth century used the coloring mandalas as a relaxation technique was Carl Gustav Jung. He prescribed his patients coloring mandalas as part of the therapy.
The benefits of coloring books for kids cannot be overestimated. It's not just entertainment, which can permanently keep the child interested, but also gives some free time for parents to make all necessary household chores; it is also an excellent developing material. Combining a game and a hobby such «coloring pages» will help improve the child's imagination, develop creative skills, visual memory and fine motor skills that will prepare a child's hand for the writing skills.