The expression of color in illustration art serves as an essential bridge between the artwork and the emotions of the audience. Its visual impact can directly influence the viewer’s emotional experience and psychological feelings. Therefore, accurately grasping the mechanism of color in conveying emotions in illustration can enhance the artistic appeal and expressive depth of the work. Human perception of color encompasses both physiological responses and psychological cognitions. This paper analyzes the relationship between the color and emotional expression in illustration art from three dimensions: the subjective emotional expression of illustration colors, the emotional projection of color imagery, and the symbolic significance of color. We hope that this exploration will inspire more illustrators to delve deeper into the realm of color and emotional expression, leading to the creation of visually captivating works that evoke strong emotional responses.