Blue Goose by Nancy Tafuri
A nice addition to the concept collection. Blue Goose, Red Hen, White Duck and Yellow Chick are on a mission to paint the barnyard while Farmer Gray is away. They mix their colors to create the secondary colors and finish just in time for Farmer Gray to bring home a new animal.
Like most of Tafuri's books, the illustrations are large and clear, making it easy to read with a child, asking questions about the animals and the colors.