Matthew的父母希望他將來當個醫生改善家裡的生活，但Matthew卻不知到自己想做什麼，直到有一天有機會參觀博物館，各類型的畫作讓他大開眼界，周遊在豐富色彩的畫作間，彷彿置身於夢境之中。遠遠看見一位美麗女士Nicoletta，Matthew深深被吸引。當天晚上做了個夢，自己與Nicoletta散步在色彩之中，好幸福……。雖然夢想發下自己仍處於家中破舊的角落，但恍然間，Matthew明白自己將來要成為一位畫家，而夢想果真實現！藝術能改變我們的世界，努力能讓夢想實現，這個故事是最好的寫照。
A cleverly told and beautifully illustrated tale of self-discovery from four-time Caldecott Honor winner Leo Lionni.
Matthew the mouse lives in a dreary corner of a dusty attic. But a trip to the museum helps him to see his surroundings in a new way. With brush in paw, Matthew sets out to paint "the shapes and colors of joy."