A word for rainbow colors

Short answer

• for the red-violet direction, frequential or frequentially ordered
• for the violet-red direction, antifrequential, antifrequentially ordered, or wavelength-ordered
• for both directions: potentially spectral, spectrally ordered, or hue-ordered, although that last one is a little more ambiguous depending on whether you consider using blends of red and violet to transition between them appropriate for rainbow ordering

Long answer

In English, we have more or less eleven color terms that we would consider other colors to be instances of: ‘black’, ‘white’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘brown’, ‘orange’, ‘pink’, ‘purple’, and ‘grey’. These colors are somewhat arbitrary, but there is a tendency among languages to prioritize certain color groupings. This is related to couple of other influences as well (that I’m not qualified to speak of), but one big factor is that
the majority of people’s eyes rely on three different types of color receptor to pick up color.

Now, colloquially we often draw rainbows with a near-subset of those, but if we want to talk about the actual colors of the rainbow, they are continuous and infinite in number. Rainbows aren’t composed of just any colors, though- no brown!- they approximate with some success what are known as spectral colors.

These are the colors you get if you shine a narrow laser into a prism- they are comprised for the most part of a narrow range of pure colors (the light is of a small range of wavelengths). The primary thing that distinguishes them is the constituent wavelength of light.

Now, rainbows aren’t composed of spectral colors (water shenanigans), but it’s close enough that we associate the colors. In the context of colors more broadly, we consider colors to be more «colorful» the closer they are to being pure- in color spaces this is known as saturation, and the dominant light frequency is known as color hue.

In the above diagram, you can see that the spectral colors are along the edge, with different wavelengths of light demarcated.

This is also why purple is only sometimes included when we talk about rainbow colors- the color traditionally most strongly associated with the word «purple» has a clear (cyclic, at least) ordering when we talk about hue, but shades of purple are as a rule less saturated than the color associated with «violet» (the bottom line of that color spectrum is even known as the «line of purple»), and so make less sense to talk about when we are talking about /actual rainbows/.

Anyway, long story short: rainbow color ordering is mostly decided by frequency (or wavelength; frequency = 1/wavelength) and so they provide appropriate terms.

From Wikipedia, the free encyclopedia

This article is about the mnemonic. For the comic book character named Roy G. Bivolo, see Rainbow Raider.

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».

History[edit]

In the Renaissance, several artists tried to establish a sequence of up to seven primary colors from which all other colors could be mixed. In line with this artistic tradition, Sir Isaac Newton divided his color circle, which he constructed to explain additive color mixing, into seven colors.^[1] Originally he used only five colors, but later he added orange and indigo to match the number of musical notes in the major scale.^[2][3]

The Munsell color system, the first formal color notation system (1905), names only five «principal hues»: red, yellow, green, blue, and purple.^[4]

Mnemonics[edit]

Isaac Newton’s color sequence (red, orange, yellow, green, blue, indigo, violet) is kept alive today by several popular mnemonics. One is simply the nonsense word roygbiv, which is an acronym for the seven colors.^[5] This word can also be envisioned as a person’s name, «Roy G. Biv».^[6]

Another traditional mnemonic device has been to turn the initial letters of the seven spectral colors into a sentence, most commonly «Richard Of York Gave Battle In Vain»^[7] (or the slight alternative «Richard Of York Gained Battles In Vain»).^[6][8] This mnemonic is said to refer to the defeat and death of Richard, Duke of York at the Battle of Wakefield in 1460,^[9] or to his son Richard III being defeated at the battle of Bosworth Field in 1485. Another sentence sometimes used is «Read Out Your Good Book In Verse»,^[10] referring to the Bible.

The color sequence may also be recalled in reverse order with the mnemonic vibgyor.^[11]

In the modern era, these traditional mnemonics have been adapted to reflect the use of the rainbow flag as a symbol of LGBT movements. In Ireland, a campaign to reduce homophobic prejudice among schoolchildren revolves around the phrase «Respect Others, You Grow By Including Variety».^[12]

References[edit]