This is a perfect addition for the coloring book, although it can be done as a single effect.
The Coloring book makes a perfect mate for this effect. After you show the Coloring book to be blank and then have the pictures appear, you now place the book down, with your right hand pick up your crayon box with the crayons showing, and cover the crayons with your left hand, as you pretend to take a handful of crayons magically out of the box (letting them fall to the bottom as they are covered with your hand) and throw them out to the members of your audience. Then after they ?magically? color the book, have them throw the invisible crayons back into the box and have them reappear.