If while coloring your child goes out of the outline, it will not be so noticeable. When the child sees how cool his result is, it will inspire confidence in him and will be a good stimulus for further work. Good coloring are those with the text in it. The text introduces the kid with the game, the kid will be interesting, while the text will expand its horizons.
Today there is a large set of coloring books. You can find coloring-cursive books, books outliners, for boys (all sorts of appliances, machines, robots, etc.), for girls (fairy-tale characters, dolls, funny funny little animals). There's even a wallpaper coloring books that opens a wide field to have enough space for young artist.