Color, an intuitive element affecting human senses, can adapt to the environment of a space, evoke emotional responses, trigger and accumulate visual experiences, and enhance the effectiveness of color in shaping spatial atmosphere and reinforcing spatial divisions. In the context of rapid urban underground space development, examining the rational application of color in underground parking spaces is crucial for improving guidance, comfort, and aesthetics. This exploration is essential for achieving high-quality development in urban underground parking environments. Based on color psychology and using typical cities in China as case studies, this paper develops a color analytical framework for urban underground parking spaces through the process of “color field investigation—analysis of color influencing factors—color system construction—color application and control” and proposes a detailed chromatographic scheme. Within this framework, color field investigation serves as the foundation for determining color usage. Key influencing factors for color selection include color elements and their relationships, the type of underground parking space, and public color perception demands. The color system has been constructed including safe colors, prohibited colors, and theme colors, which has been further divided into basic, auxiliary, and accent colors. This study provides a replicable and practical theoretical and applied framework for urban underground space management and urban color planning. The framework facilitates the establishment of a standardized color system and chromatographic scheme that aligns with urban aesthetics and public psychology, thereby improving development quality and supporting the high-quality development of urban underground spaces.

With the global economic restructuring and the consequent population mobility, urban shrinkage has become a common phenomenon. The Qinling–Daba Mountains, a zone with a key ecological function in China, have long experienced population decline and functional degradation. Clarifying the dynamics and influencing factors of urban shrinkage plays a vital role in supporting the sustainable development of the region. This study, using permanent resident population growth rates and nighttime light data, classified cities in the region into four spatial patterns: expansion–growth, intensive growth, expansion–shrinkage, and intensive shrinkage. It further examined the spatial characteristics of shrinkage across four periods (2005–2010, 2010–2015, 2015–2020, and 2020–2022). A Geographically and Temporally Weighted Regression (GTWR) model was applied to examine core influencing factors and their spatiotemporal heterogeneity. The results indicated the following: (1) The dominant pattern of urban shrinkage in the Qinling–Daba Mountains shifted from expansion–growth to expansion–shrinkage, highlighting the paradox of population decline alongside continued spatial expansion. (2) Three critical indicators significantly influenced urban shrinkage: the number of students enrolled in general secondary schools (X₅), the per capita disposable income of urban residents (X₇), and the number of commercial and residential service facilities (X₁₂), with their effects exhibiting significant spatiotemporal heterogeneity. Temporally, X₁₂ was the most influential factor in 2005 and 2010, while in 2015, 2020, and 2022, X₅ and X₇ became the dominant factors. Spatially, X₇ significantly affected both eastern and western areas; X₅’s influence was most pronounced in the west; and X₁₂ had the greatest impact in the east. This study explored the patterns and underlying drivers of urban shrinkage in underdeveloped areas, aiming to inform sustainable development practices in regions facing comparable challenges.