You can find many materials from the Internet and it could be both positive and negative. However, coloring pages are positive sides of the Internet. May be think about coloring is not such a brilliant activity but if you consider children especially toddlers, it will be very creative and didactic game.
When you write to Internet something related with toddler coloring, you could find thousands of websites and different types of categories. For example, when you choose alphabet in a painting pace, you will see lots of shapes and each shape has own letter in itself. Also, if you select animal part, you will meet many animal figures. Because of the fact that this coloring game has an informative side so you can teach alphabet or animals to your children. Before the going to school, they would know alphabet so this situation will make them one step ahead of their peer.
After your children colored these any kind of picture, you can print it out and hang to their wall. Thus, seeing what they have done will make them more eager for new paintings. Also, you can print them before the coloring; it depends on your pleasure. The most important difference with ordinary painting and this kind of coloring exercises is children will learn something. For example, when you give to the child crayons and a blank paper, the child will draw something in his or her mind. However, the child is very young and do not know the name of flowers or days of week, you can teach all that kind of stuff to the child via coloring pages.
Overall, you should not ignore these kinds of activities and you need to take it seriously because coloring is also part of education. Kindergarten is a good example of it because it is a school of playing games and coloring stuffs.