Hello, Red Fox by Eric Carle

Based on Johann Wolfgang von Goethe's color theory of primary colors and complementary colors, Mr. Carle creates a visually involved story.
Little Frog invites various creatures to his birthday party.  When each creature arrives, Little Frog and his Mama disagree on the animal's color.
Readers must stare at a black dot for 10 seconds and then stare at a blank paper with a black dot in the center to see the complementary colors.
My boys loved it!
I would not recommend this book for younger kids or a large group story time as appreciating it takes time and effort.
*Borrowed from the library.