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 green for certain computer uses. "Fern green" is a color that resembles ferns. A Crayola crayon named "fern" was created in 1998, which is a lighter shade of the top color shown on the right. The first recorded use of "fern green" as a color name in English was in 1902. "Forest green" refers to a green color said to resemble the color of the trees and other plants in a forest. The first recorded use of "forest green" as the name of a color in the English language was in 1810. Displayed at right is the color "green earth". "Hooker's