Peace, Baby! by Linda Ashman, illustrated by Joanne Lew-Vriethoff is a calm, laid-back book. It encourages children to pick another way to deal with conflict than shouting, or hitting, or any number of reactions many children have when things don't go their way. (OK on that note, it could be for anyone, not just kids)
The artwork is rendered in pen & ink and Adobe Photoshop. The cool, pastel colors have a pop of brighter color here and there, but mostly the illustrations are as sedate as the message.
I'll use this in Storytime and encourage parents and teachers to use this as an additional title for the 'conflict resolution' themes they need.