Because of its better insulation than clear glass, swatch glass can block more heat penetration, also known as thermal control glass, which is often used in public works. The method is to add various metals and metal oxides to the glass to change the color of the glass.
For example, a small amount of manganese can change the light green color caused by iron in the glass, and a little more manganese can cause the lavender glass. Selenium also has a similar effect.
A small amount of cobalt can cause blue glass.
Tin oxides and arsenic oxides can cause opaque white glass, which appears to be a white ceramic.
Copper oxides cause cyan glass. Metallic copper creates a deep red, opaque glass that looks like a ruby.
Nickel can cause blue, deep purple, or even black glass.
Titanium can cause a brownish yellow color.
The amount of gold (about 0.001%) caused by the glass is very sharp, like the color of ruby.
The glass caused by uranium (0.1% to 2%) is firefly yellow or green.
Silver compounds can cause orange to yellow glass.
Most of the swatches used in construction are mainly in four colors: brown, green, gray and blue.