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.
Coloring pencils or markers are useful for the development of fine motor skills. After painting the small objects, the child learns not to go beyond the boundaries of the drawing and trace the thin lines.