1：Experimental Design and Method Selection:

The pigments were synthesized using the conventional high temperature ceramic route. Raw materials (SrCO3, BaCO3, CeO2, Tb4O7) were mixed in stoichiometric ratios, wet mixed in acetone, dried, and heat treated at 1250°C (Sr2-xBaxCe

2：6Tb4O4) or 1300°C (Ba2Ce1-xTbxO4) for 6 hours. Sample Selection and Data Sources:

Compositions with general formulae Sr2-xBaxCe

3：6Tb4O4 (x = 25, 50, 75, 0, 25, 50, 0) and Ba2Ce1-xTbxO4 (x = 0, 20, 40, 60, 80, 0) were prepared. List of Experimental Equipment and Materials:

Equipment included powder X-ray diffractometer (PANalytical X’pert Pro), XPS (PHI 5000 Versa probe II), SEM (JEOL JSM-5600 LV), EDS (Carl Zeiss EVO18), particle size analyzer (Anton Paar Litesizer 500), UV-vis NIR spectrophotometer (Shimadzu UV-3600), TG/DTA (SII Nanotechnology Inc. 6200), and portable spectrophotometer (Hunter Lab Miniscan EZ4000S). Materials included SrCO3, BaCO3, CeO2, Tb4O7 (Sigma-Aldrich,

4：99% purity), PMMA, acrylic acid, polyurethane, and concrete slabs. Experimental Procedures and Operational Workflow:

Synthesis involved mixing raw materials, drying, and heat treatment. Characterization included XRD for phase purity, XPS for oxidation states, SEM for morphology, EDS for elemental analysis, particle size analysis, UV-vis NIR for reflectance and band gap, TG/DTA for thermal stability, and chemical stability tests in acid/alkali/water. Application studies involved dispersing pigments in PMMA and coating on concrete slabs.

5：Data Analysis Methods:

Band gap was determined using Tauc plot method, NIR solar reflectance calculated using ASTM Standard G173-03, color coordinates obtained using CIE1976 L*a*b* system, and chemical stability assessed by color difference (ΔE*ab).