Coloring boos must be such as to cause a positive emotional response from the child, encourage him to draw further. For older children it is interesting to color a favorite fairy tale character, useful educational coloring.
In the process of painting you focus your attention on a subject that is at your fingertips. If you do it with enough concentration, it will ignore the extraneous noise, unpleasant thoughts and worries. This is a very useful skill that will be useful in situations where you need to briefly forget about your physical or emotional pain.