You can metaphorically take a page out of a coloring book, and break up the work into a few sections. Each team member or group within the team should first be instructed on which part of the page they are going to color, let them know what color they can use, and when their turn will come up. Next, after each team member has finished their part of the coloring than take the completed picture and hangs it up so that every one can see their part of the picture and the entire teams contribution.
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 repetitive, low-stress, and "no brainer" act of color lends itself to relaxation. The calming effects not only helps to reduce stress levels, but also can help to bring you back to your youth. The awesome part is that anyone can do it will no skill set required! Grab a crayon and you are good to go. You can make it even more enjoyable and have your kids or grandkids color with you. Depending on the age of the young ones they may be interested in the adult coloring books, others still wanting to color a cow, astronaut, or pretty flower arrangement.