The advantages of coloring pages:
1) Self expression - coloring on a blank "canvas" (notepad), is a method for children and adults alike to express themselves. You can tell a lot about the method a person is feeling by the images that they draw, the colors that they use, etc. It is important to offer children an opportunity to express themselves, and not all children express themselves through words and through writing, lots of use art.
2) Color acknowledgment
3) Treatment - for many individuals (myself consisted of) coloring is healing. Regardless of whether it's doodling, or coloring the "finest picture ever", coloring can be a method to de-stress, after a hectic morning of school work, unwind, and cool down, after the tensions of a day at school or work.
4) Grip/Control - lots of children discover how to hold a pencil, pen, marker, or colored pencil, by very first learning how to hold a crayon. The little muscles needed for penmanship later start to be developed while coloring.
6) Structure motor skills
7) Focus - Focusing on a single job for a length of time is necessary for coloring and for all sorts of things throughout one's life.
8) Boundaries - Another thing that children gain from coloring pages, with preprinted photos on them, is how to accept borders. While a toddler or preschooler may scribble all over a coloring sheet, without any regard for the borders (lines on the coloring page), as the kid ages, they will start to appreciate those lines, and make an effort to color in between them. While I motivate blank paper coloring totally free expression as often as possible, for lots of young children pre-printed coloring pages are their very first exposure to printed borders. This early exposure to borders in print, will be a substantial help when handwriting time comes around, and the kid has to appreciate the borders of the preprinted handwriting lines on the paper.
9) Milestone - This is the last little "importance" of coloring that I will mention for now, which is that coloring in the lines is a milestone, a sense of achievement, the initial step towards a successful scholastic profession for lots of children. For lots of children coloring in the lines is just as important as counting to 10, counting to 100, reciting the alphabet, discovering the multiplication truths, and so forth. It's a milestone that states "yes I can" do whatever I come across, and it offers children with pride, a sense of self worth, and assists them to feel accepted in a society that is often quick to judge, and slow to react. This sense of achievement will carry them through life, and assist them not to give up so easily, when something brand-new comes along.