Two siblings wake up in two very different moods; the older one cheerful and lively, the younger feeling sad and irritable. The big sister negotiates and cajoles, tries everything she can think of to cheer her little sister up, but nothing works. She offers to go outside and play, but her sister refuses. She suggests they color a picture, but her little sister only likes the color gray. She proposes they bake sweet cakes, but her sister only wants sour ones. It’s only when little sister’s gloomy mood reaches a boiling point that the older sibling tries a different tactic. She empathizes and enters the gloom with her sister, and offers up compassion along with a gray picture and a sour cake. Together, they navigate the little sister’s grim, messy feelings until the siblings are able to play. Told in striking, conceptual illustrations, this story explores empathy, emotional acceptance, mental health, and acknowledging difficult feelings in a warm, accessible way.