Research on the architectural color characteristics of the Forbidden City in Beijing

Architectural color systems are important carriers of urban cultural identity and play a key role in heritage conservation. Existing studies on architectural color are largely qualitative or perception-based, with limited integration of quantitative measurement and multi-scale spatial analysis. This study develops a quantitative and multi-scale analytical framework to investigate the architectural color system of the Forbidden City in Beijing. The research integrates spectrophotometric measurement with physical color-card comparison based on the Munsell color system, enabling reliable and standardized color data acquisition. A three-level spatial framework is adopted, including the macro-scale palace complex, meso-scale functional zones, and micro-scale individual architectural elements. Based on field measurements and systematic analysis, Munsell color coordinates (Hue, Value, Chroma) were obtained across architecture, landscape and pavement. The results reveal clear patterns of color distribution across spatial scales, as well as consistent relationships between dominant color combinations, Cosmological and Imperial System, the Wu Xing philosophy, Architectural Hierarchy, Functional Differentiation, and Material and Construction Constraints. In particular, characteristic color sequences and material–color associations are identified, reflecting the hierarchical organization and compositional logic of imperial architectural color. This study provides a systematic and data-driven approach to architectural color analysis, bridging instrumental measurement, perceptual color systems, and spatial interpretation.