Interface Color Design Under Changing Lighting Conditions: Effects on Visual Search and User Experience

Interface color design must balance visual search performance, visual demand, and user experience under changing lighting conditions, yet these factors are often studied separately. We examined their joint relationships in a 3 × 2 × 12 within-subject experiment using a simplified four-block visual-search task with 20 adults. Behavioral, eye-tracking, and subjective measures showed dissociable response patterns. Search time varied with the interaction between ambient illuminance and display configuration, whereas accuracy remained near the ceiling despite a small illuminance-related effect detected in the trial-level analysis. Eye-tracking measures, especially pupil diameter change, were sensitive to lighting and screen configuration. By contrast, the tested color conditions, which also varied in target–background perceptual color difference (ΔE), were not reliably associated with search efficiency but significantly affected single-item satisfaction and task-specific perceived-usability ratings. These findings support multimodal evaluation of implemented interface color configurations under changing lighting conditions, while indicating that the observed effects should be interpreted as effects of evaluated interface configurations rather than as isolated effects of hue, ΔE, luminance, or display polarity.