A new inorganic pigment based on rare earth phosphate has been synthesized with the goal of preparing ecologically and environmentally friendly specific pigments. A yellow-green pigment that consists of nontoxic elements was obtained by doping calcium ions into the cerium orthophosphate lattice. Characterizations using XRD, UV-vis spectroscopy, and colorimetric assessment revealed that the formation of a Ca-doped CePO4 solid solution was responsible for the appearance of the color.