Children's books come easier. At least on the cover. The illustration by which the cover comes from, is a whole different story.
I started here with the ant and colors.
For the kids that this book is targeted for I love the primary(red, yellow, and blue) colors with a few secondary colors(green, orange, and purple) too.
Pick my favorite from inside and make that a cover. Put the picture my son took of me on the back and there we go.