It is believed that the company The McLoughlin Brothers (en.wikipedia.org/wiki/McLoughlin_Brothers) invented the coloring books. They published a book called The Little Folks' Painting Book in collaboration with Kate Greenaway in 1880.
If wallpaper coloring can be used only within a child's room, the «coloring pages for kids» can be easily printed out and your kid can take it anywhere: outside and when visiting someone. They will be useful everywhere, the baby will not be bored, and could spend time with an advantage. If you have internet access, then the child can offer coloring online. This type of coloring will get your child interested, because they also include some tips.