Observe what colors your child is familiar with when they watch the characters as they meet them on a cartoon. Please note that the kid paints his favorite characters accurately and thoroughly.
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.