You have a greater tool - your PC - that can be helpful to get the printouts of diverse colorful sheets. Guide the children, exclusively during the holidays to add illustrations to the colorful-page, and showcase them around the prominent places of the house. This will give them, a sense of pride and joy for their creativity, and would lead to further productive pursuits. Thus, you will witness that there are massive advantages of coloring-page relatively to coloring books. Coloring sheet are economical, costing you only a couple of cents in ink and paper rather than a few dollars for a coloring book.
The art of coloring is a simple joy. All you need is a coloring book and your choice of tools. From here you can immerse yourself fully into the craft without agonizing about what to make, how to read the pattern, and how will it turn out? Coloring is a a form of meditation. There is something truly hypnotizing that happens with you sit down with a fresh box of pencil crayons, choose the color that jumps out at you and begin your journey into the page. Time loses its grip on the mind and enables the color-er to become present in the moment, in the line and in the color gliding onto the paper.