## 3 Research Area and Methods
### Sample Collection and Research Method  
The research methods employed in this study center around the chromaticity measurement of images [37]. These methods enable precise and calibrated assessment of the visual attributes of samples. This research uses meticulous data analysis to extract the color spectrum that aligns with the traditional hues found in landscapes associated with ethnic minority groups. Researchers make field observations, photographs, and video recordings of landscape elements such as buildings, mountains, water bodies, vegetation, etc., extract image and image color information (removal of color deviations caused by weather, light, cameras, and other related factors), establish a color database for observation points, and analyze and summarize database information. Then, the current color database can be summarized to objectively reflect Xiangcheng County. The landscapes in the research were classified into landscape aerial view, residential buildings, religious buildings, streets, farmland, and local materials [38; 39; 40]. Moreover, the landscape was segmented into three categories according to the distance of sight: distant view, middle view, and nearby view [41; 42] The distant view type is mainly an aerial view;the middle view type includes residential and temple buildings, streets, and farmlands; and the nearby view type mainly includes the local material details of landscape architecture (Table 1). \begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Landscape View** & **Color Landscape Elements** & **Basis and Key Points for Sample Selection in Xiangcheng** & **Sources** \\ \hline Distant view & Aerial View & **Large-area color landscape data are selected from commanding heights in the core area of Xiangcheng by a bird’s-eye view to collect: S1 and S2.** & A bird’s-eye view can provide a color layout of the main study area [43; 44; 45]. It can also observe the overall harmony and contrast of colors in natural and man-made environments—for example, the color boundaries between urban and natural areas [46]. \\ \hline Middle view & Architecture & **The local representative residential buildings and temples are selected, almost designed and constructed by local people: S3, S4, S5.** & Architecture is an integral part of the urban/rural landscape, and architectural color becomes the protagonist of urban/rural color [47; 48]. It sometimes even determines the color construction of the entire city/countryside [49]. \\ \hline Street & **This study selected streets with core landscape nodes: S6, S7, and S8.** & Streets are landscape corridors and important activity spaces in cities, and their color analysis helps to understand the vitality and functionality of cities and rural areas [50; 51]. This analysis includes pavement materials, street twees, street buildings, and other elements [52]. \\ \hline Farmland & **This study selected angles that can reflect the overall farmland layout and detailed characteristics of the crop landscape: S9, S10, and S11.** & The changing colors of farmlands reflect the changing seasons and the type of agricultural activity [53]. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Sample classification and selection basis. From 6 different landscape perspectives, a total of 14 color-area ratio samples were selected from landscape research area and numbered S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14, respectively (Table 2). The selection process was conducted by interviewing three landscape design specialists who research color landscape design and cultural heritage protection. The sample comprised 58 pictures, among which 14 samples were selected.