Towards Sustainable Conservation: Balancing Commercial and Historical Colors to Revitalize Historic Districts

In the current context of urban regeneration, how to sustainably revitalize historic districts through balancing commercial development and historical conservation is a critical issue. As an indicator reflecting the comprehensive quality of the built environment, pedestrian behavior predicts the efficacy of urban regeneration. To seek the best practice of balancing commercial and historical elements, evaluations on the influence of different façade color relationships on pedestrian behaviors are needed. Focusing on the color dimension of street facades, this study constructs a systematic research framework linking facade color relationships and micro-scale pedestrian behaviors. In the aspect of color relationship evaluation, color is decomposed into Commercial Color Harmony (CHc), Complexity (Cc), and Order (Oc) to describe facade color relationships. In the aspect of pedestrian behavior measurement, trajectory detection technology is leveraged to describe micro-scale behaviors, focusing on Trajectory Diversity (TD), Trajectory Complexity (TC), Ratio of Searching Behaviors (Rs), Stay Intensity (Is) and Average Velocity (Va). Taking typical historic districts in Nanjing as a case study, this study first employs fuzzy-set Qualitative Comparative Analysis (fsQCA) to reveal the associations between facade color relationships and pedestrian behaviors. Then regression analysis is included to verify the numeric associations between color relationships and pedestrian behaviors. The results suggest that CHc exhibits an inverted U-shaped relationship with pedestrian behaviors, indicating that an optimal range of balance between commercial and historical colors, together with active storefronts, is associated with richer pedestrian activities. This research provides evidence-based insights for sustainable historic district conservation and regeneration by suggesting that color management should avoid excessive constraints on commercial vitality.