ROYGBIV is an acronym for the sequence of hues commonly described as making up a rainbow: red, orange, yellow, green, blue, indigo, and violet. When making an artificial rainbow, glass prism is used, but the colors of "ROY-G-BIV" are inverted to "VIB-G-YOR". There are several mnemonics that can be used for remembering this color sequence, such as the name "Roy G. Biv" or sentences such as "Richard of York Gave Battle in Vain".