You would think that paint by number would decrease creativity in children, but I've found the opposite to be true. My son learned how to shade horses by doing a paint by number. We bought the kit at a craft supply store. The thin canvas has an outline of the picture, with numbers inside each area. The number corresponds to a color. For example, number 8 is light blue. You go ahead and paint each area the correct colors until you finish the painting.
Later on I noticed that my son was drawing horses freehand. When he colored in the horses with colored pencils, he shaded the mane in the same way that he did for the paint by number. So his artistic skill increased because of the paint by number. Now the beautiful painting of horses can be seen in the hallway of our home. (Actually, another son painted the horses in my hallway. We gave the collection of horses as a gift to Grandma, who owned horses for years. You can see one of our horse paint by numbers in the YouTube video “Hallway Art Gallery.”)