ROYGBIV

ROYGBIV is an acronym for the sequence of hues commonly described as making up a rainbow: red, orange, yellow, green, blue, indigo, and violet. 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". The battle is the Battle of Wakefield in 1460 which killed him.