Little Blue lives with his blue family but one day a moving truck arrives with a yellow family, which no one in the blue town had seen before. Little Blue wants to play with Little Yellow, but their mothers don't allow it since they have different colors. The boys sneak off to play together and have so much fun running and digging that they hug each other very tightly and turn green. The green boys are not recognized by their mothers. They cry in sadness until their colors come back, then hug and turn green again. The community realizes color doesn't matter.