Color and Major Depressive Disorder ( <scp>MDD</scp> ): Evidence for the Effects of Value on Color Preferences in Depression

ABSTRACT Objective This study examines how major depressive disorder (MDD) influences color value/lightness preferences. It explores whether differences in value/lightness selection between MDD and nondepressed (ND) may serve as a potential psychological marker for mood‐related disorders and their implications for therapeutic design. Method A 3D‐modeled healthcare environment was presented to 37 ND and 20 participants with MDD. Participants selected wall colors by adjusting the value component in the RGB‐HSV color space for 10 hues at maximum saturation, in response to four questions: preferred consulting room color, favorite color, color evoking happiness, and color evoking sadness. To enhance perceptual accuracy, the data were also converted to the CIELAB color space for analysis. Data analysis included repeated‐measures ANOVA, Spearman correlation, and machine learning (ML) classification. Results The most significant differences in both HSV value and CIELAB lightness were observed in sadness‐related color choices, indicating that individuals with MDD and ND differ more strongly in this emotional context. Participants with MDD associated higher‐value blue and green with sadness. They also preferred a higher‐value red for happiness but chose a lower‐value orange as their favorite and the one they preferred to use in their consulting room. Spearman correlation analysis showed significant correlations between Beck Depression Inventory (BDI) scores and value/lightness selections. Moreover, ML classification achieved 78.9% accuracy in distinguishing MDD from ND individuals. Conclusion Color preferences, particularly those tied to emotional responses, may serve as nonverbal psychological markers for mood disorders. MDD participants' choices suggest a preference for colors that reinforce negative emotional states. Future research should explore the generalizability of these findings. Application Integrating color preferences into therapeutic design could enhance emotional well‐being in healthcare settings. ML‐based color analysis may offer a noninvasive tool for mood assessment in clinical psychology, pending further validation.