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.
There is another advantage of colorings for adults. Most of them are very nice and include impressive black-and-white contours that can be turned into a work of art. Imagine the feeling of satisfaction that you get when you have finished drawing and will be able to appreciate the beauty of the masterpiece created by you personally.