Leo Lionni is one of my absolute favorite authors of children's books--and this book, Little Blue and Little Yellow, is my favorite of his books. But I have this thing about stories that involve abstract shapes as their main characters ( you too? you should read about Little Smudge then...).
The story is about our two heros--who just happen to be ragged edged circles in blue and yellow--and follows them through a colorful afternoon of simple, but beautifully illustrated games, and then their surprise afternoon when they hug and find themselves merged into an all new color...and the confusion that ensues from there.
Apparently, Leo Lionni conceived this book when he was with his grandkids on a train and they were making a bit too much mischief, so he created a story right then and there with what he had--a magazine. He tore some ads into pieces and began to tell them them this story about little blue and little yellow...and this classic was born.
Just goes to show you what we all know, the best things come from some of the simplest means--and also, necessity is the mother of invention...any other cliche's I should be hitting on here? Whatever the case, go find a copy of this at your library if you have not read it before--I promise you will enjoy it.