interior wall color and emotional responses: evidence from group therapy rooms

Color, as an environmental stimulus, shapes emotional experience in architectural spaces and is critical in group therapy rooms, where spatial conditions must support psychological safety, cohesion, and emotion regulation. this study examined the effect of interior wall color, systematically varied as the sole manipulated variable, in an immersive virtual reality (vr) simulation of a group therapy room. in a within-subjects design, 57 participants experienced 17 wall-color conditions of the same virtual room. emotional responses were measured with the self-assessment manikin (sam) and interpreted within the pad (pleasure–arousal–dominance) framework, focusing on valence and arousal. given the within-subjects design and the ordinal nature of sam ratings, data were analyzed using nonparametric statistical methods, including the friedman test, which is robust to violations of normality in repeated-measures comparisons, and spearman correlations, alongside cluster analysis. wall color significantly influenced valence: in post hoc comparisons with holm-adjusted p values, dark green and turquoise green yielded higher valence ratings than dark red and light red, whereas effects on arousal were weaker. although several other hues showed relatively higher pleasantness descriptively, the strongest inferential contrasts emerged for dark green and turquoise green. at the color-category level, cool colors elicited higher valence than warm and neutral colors. cluster analysis yielded seven emotional profiles, providing a finer-grained description than the warm–neutral–cool classification. correlation analyses indicated that hues (dark cream, turquoise green, light blue, light cream, and dark green) produced coherent valence–arousal profiles, whereas others were associated with heterogeneous responses. these findings suggest that interior wall color can structure the emotional experience of group therapy rooms and that color choices guided by pad-based response patterns may support evidence-based design of therapeutic spaces, moving beyond aesthetic intuition.