Painting will be very helpful for people with post-traumatic syndrome, or those who are constantly in a stress state. The fact that such activity calms the amygdale, i.e. the area of the brain that is responsible for generating emotions. When you focus on coloring pictures, you give your brain a chance to rest and relax.
Coloring, of course, cannot be banned. You should not exclude its use for fine motor skills; this activity allows parents to get an extra half an hour of free time.