Trivial name for example, hydrogen ("water-producing"), oxygen ("acid-producing"), nitrogen ("soda-producing"), bromine ("stink"), and argon ("no reaction") were based on Greek roots, while the names of iodine and chlorine were derived from the Greek words for their characteristic colors. Indium, rubidium, and thallium were similarly named for the colors of particular lines in their emission spectra. Iridium, which forms compounds of many different colors, takes its name from "iris", the Latin for "rainbow". The noble gases have all been named for their origin or properties. Helium comes from the Greek "helios", meaning "sun" because it was first detected as a line in the
Shades of cyan verdigris was the most vibrant green pigment available and was frequently used in painting. Verdigris was sometimes used to illustrate cyan colors in early color wheels. Viridian is a blue-green pigment, a hydrated chromium(III) oxide, of medium saturation and relatively dark in value. It is composed more of green than blue. Specifically, it is a dark shade of spring green, the color between green and cyan on the color wheel, or, in paint, a tertiary blue–green color. Viridian takes its name from the Latin "viridis", meaning "green". The first recorded use of "viridian" as a color name in English was