Barnes & NobleOne by Kathryn Otoshi

Blue is a quiet color. Red's a hothead who likes to pick on Blue. Yellow, Orange, Green, and Purple don't like what they see, but what can they do? When no one speaks up, things get out of hand - until One comes along and shows all the colors how to stand up, stand together, and count. As budding young readers learn about numbers, counting, and primary and secondary colors, they also learn about accepting each other's differences and how it sometimes just takes one voice to make everyone count.