Here are some tips on using crayons for effects in coloring: You can start with a light layer of the color you want to use first. Then you can cover that with darker or lighter color to add life to your drawing, just like the wings on this butterfly.
A few years ago, I wrote a book about realistic crayon drawings. What a joy it was to create, for I had brought my childhood dream into my adult professional life. I wanted to share it with others, for few knew that crayons are actually a wonderful fine art medium. They're not just for kids!