When painting figures (for example, from 1 to 10) it develops a color perception, fine motor skills, attention, diligence and accuracy, mathematical ability. Such tasks are connected to the process logic of painting, allow to fix the basic math skills or letters.
There is another advantage of colorings for adults. Most of them are very nice and include impressive black-and-white contours that can be turned into a work of art. Imagine the feeling of satisfaction that you get when you have finished drawing and will be able to appreciate the beauty of the masterpiece created by you personally.