This study explores the complex interplay of aesthetic sensibility, color psychology, and design self-efficacy among 61 preschool teachers in visual teaching aid design. Using structural model analysis, it assesses how aesthetic sensibility impacts color psychology and design self-efficacy, and examines color psychology’s potential mediating role. Findings show aesthetic sensibility strongly and significantly affects both color psychology (β = 0.749, p < .001) and design self-efficacy (β = 0.759, p < .001). Unexpectedly, color psychology does not significantly influence design self-efficacy (β = 0.071, p > .05), questioning its mediating role. Rigorous methods, including confirmatory factor analysis and structural equation modeling, validated the measurement model and tested hypotheses. All variables showed satisfactory reliability and validity, with VIF values indicating no multicollinearity issues. These results enhance theoretical understanding of how aesthetic capabilities boost teachers’ confidence in designing visual materials and offer practical insights for teacher education. Enhancing preschool teachers’ aesthetic sensibility may be key to improving their design of effective teaching aids, though color psychology’s role requires further exploration. These findings provide valuable guidance for educators and policymakers to develop targeted interventions, ultimately improving early childhood education quality.