About 2/3 to 3/4 of Cadmium produced worldwide is used in the production of Ni-Cd Batteries. About half the remaining consumption or 2,000 tons annually, is used to produce colored Cadmium pigments. The principal pigments are a family of yellow/orange/red cadmium sulfides and sulfoselenides. Brilliantly colored, with good permenence and tinting power, Cadmium Yellow, Cadmium Orange, and Cadmium Red are familiar artist colors, but of little use in architectural paints. Their greatest use is in the coloring of plastics and specialty paints which must resist processing or service temperatures up to 300C. The color-fastness or permenence of Cadmium requires protection from a tendency to slowly form carbonate salts with exposure to air. Most paint vehicles accomplish this, but Cadmium colors will fade in fresco or mural painting. Cadmium pigments can also color glass and ceramic glazes, not by solution, but colloidal dispersion within the glass. The lenses of red stoplights use this technique.