As the first Italian painter to win the Hans Christian Andersen Illustration Award, Robert Innosenti's bold and substantial picture book topics and consistent realistic style have to some extent filled the gap in the field of picture book illustration. This article takes "Erika’s Story", "Rose Blanche" and "The House" as core samples, and analyzes the application and treatment of colors in Innovent's picture books from two perspectives: the overall color tone selection of the picture books and the color changes in the pictures surrounding the emotional ups and downs. It explores how colors in his works express narrative emotions, convey important information to the viewers and guide their emotions.