In this work, the author painted the cat black to show his death. In life, people often use colors to express certain emotions because of their psychological association with colors. For example, red represents warm and cheerful feelings or lively atmosphere, blue represents sad and melancholy feelings or quiet atmosphere, and black has many meanings such as solemnity, dignity and death. But why the author uses the cat to symbolize death, besides the emotional expression of color, it should also be related to the meaning of the image of the cat.