The benefits of coloring pages:
1) Self expression - coloring on a blank "canvas" (piece of paper), is a way for kids 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 give kids an opportunity to express themselves, and not all kids express themselves through words and through writing, lots of use art.
2) Color recognition
3) Treatment - for many people (myself included) coloring is healing. Regardless of whether it's scribbling, or coloring the "best photo ever", coloring can be a way to de-stress, after a busy early morning of school work, unwind, and calm down, after the stresses of a day at school or work.
4) Grip/Control - lots of kids discover how to hold a pencil, pen, marker, or colored pencil, by first learning how to hold a crayon. The little muscles needed for penmanship later begin to be established while coloring.
6) Structure motor abilities
7) Focus - Taking note of a single task for a length of time is essential for coloring and for all sorts of things throughout one's life.
8) Limits - Another thing that kids learn from coloring pages, with preprinted photos on them, is how to accept borders. While a toddler or preschooler might scribble all over a coloring sheet, with no regard for the borders (lines on the coloring page), as the kid grows older, they will begin to appreciate those lines, and make an effort to color between them. While I motivate blank paper coloring free of charge expression as typically as possible, for lots of preschoolers pre-printed coloring pages are their first exposure to printed borders. This early exposure to borders in print, will be a huge aid 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 "significance" of coloring that I will mention in the meantime, which is that coloring in the lines is a turning point, a sense of achievement, the primary step towards a successful academic profession for lots of kids. For lots of kids coloring in the lines is just as crucial as counting to 10, counting to 100, reciting the alphabet, finding out the reproduction truths, etc. It's a turning point that says "yes I can" do whatever I discover, and it offers kids with pride, a sense of self worth, and assists them to feel accepted in a society that is typically fast to judge, and slow to respond. This sense of achievement will carry them through life, and help them not to quit so quickly, when something new occurs.