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.
Portability: Such products have to be portable. Whenever you get the time, you can do this activity. To your surprise, there are many people that carry these books to their offices as well, so that they can use them or do a little bit of coloring whenever they are on tea or coffee breaks. It helps them relax their office stress. Available in various colors: From black to white, from peach to pink, there are different shades in which the portable books are available. Once you go through the entire gallery, you can select the best one for yourself from the list. Right when such a thing is delivered to you, the activity can be started whenever you are ready.