Against the backdrop of China's underdeveloped children's life cognition education system and the "insufficient color adaptability" of traditional carriers, children's color psychology provides a scientific basis for the visual design of life cognition picture books. Taking the original picture book Good Things Happen as an example, this paper explores the application of this theory through literature research, case analysis and design practice. Based on children's color perception development characteristics and combined with the picture book's narrative framework, the study constructs a stage-adaptable color design scheme. Verified by practice and feedback, this application can alleviate children's anxiety about themes such as family separation, convey the cognition of "life continuity", and provide practical reference for the color design of similar picture books.