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.
If while coloring your child goes out of the outline, it will not be so noticeable. When the child sees how cool his result is, it will inspire confidence in him and will be a good stimulus for further work. Good coloring are those with the text in it. The text introduces the kid with the game, the kid will be interesting, while the text will expand its horizons.