How do cadmium sulfide and cadmium selenide produce a true red ceramic pigment?

A true red ceramic pigment is produced using solid solutions of cadmium sulfide (CdS) and cadmium selenide (CdSe). While cadmium sulfide alone is a bright yellow pigment, the inclusion of cadmium selenide allows for the creation of stable colors ranging from yellow to bright red.12

In the context of materials science, these compounds function as pigments because they absorb specific wavelengths of light, which imparts color to the material. By varying the conditions during the precipitation of these compounds, manufacturers can control the resulting hue, which may also include additives such as barium sulfate to achieve specific shades ranging from light red to maroon. These pigments are incorporated into ceramic bodies or glazes, where their thermal stability and chemical inertness during the firing process are essential for maintaining the desired color.132