Idioms Referring to Colors of the Rainbow

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The six colors of the spectrum have contributed significantly to expressions and turns of phrase that are themselves often quite colorful. Here’s a sampling of idioms employing the words for colors.


Because of the association of the color red with danger and deficits, most idioms that include the word red — for example, “in the red” (meaning “in debt”) “red tape” (referring to bureaucratic complications), and “seeing red” (being so angry that one’s vision is blurred) — have negative associations.

However, they overshadow a few positive ones: “paint the town red” (enjoying oneself dining and drinking), “red-letter day” (an occasion for celebration), and “red-carpet treatment” or “roll out the red carpet” (referring to paying special attention to someone, based on the color of carpeting usually seen at the entrance to a gala event for celebrities or VIPs).

A red herring is a deliberate diversion, a red-eye flight is a late-night airplane trip (from the bloodshot eyes of tired passengers), and to have a red face or to go beet red is to be embarrassed.


Among the colors of the rainbow, orange is curiously absent from idiomatic usage. Although it is a bright, cheerful color often found in nature, the only common expression that uses the word orange employs the plural form referring to the fruit of that name –“apples and oranges,” meaning “unrelated subjects or issues,” to emphasize irrelevance.


The few idioms incorporating the word yellow have negative connotations. To have a yellow belly or a yellow streak down one’s back (the reason for the choice of locations is obscure) is to be a coward, and yellow journalism, based on an early comic strip character named the Yellow Kid, is that which is sensational and/or biased.


The phrases “green-eyed monster,” an epithet for jealousy, and “green with envy” are perhaps based on the idea that one’s complexion turns a sickly hue when feeling these emotions; similarly, to say that someone looks green (or is green around the gills) means that they appear to be sick.

But green also has positive connotations: To give someone the green light, based on the universal traffic-signal color to indicate “Go,” is to approve a proposal. If you have a green thumb (or, in British English, green fingers), you are adept in gardening — probably because successful gardeners are apparent from the green pigmentation that rubs off from healthy plants to their hands as they handle the vegetation.

Because US paper currency is green, in American English, the color is associated with money and wealth.


Because it is the color of the sky, blue is associated with idioms such as “out of the blue,” “like a bolt from the blue,” and “out of a clear blue sky” that refer to a person, thing, or idea that arrives as if from nowhere. (“Into the wild blue yonder,” meanwhile, refers to a venture into unknown territory.)

“Blue collar” connotes people who work at a trade or as laborers, because such workers at one time commonly wore durable shirts made of blue cotton (as opposed to “white collar,” referring to dress shirts worn by professionals and office workers, and “pink collar,” a later, now frowned-on, reference to women in clerical positions, so labeled because men rarely wore pink.)

Two idioms generally negative in sense include blue-blooded, meaning “aristocratic,” probably because during the era in which the term was coined, nobility tended not to spend time in the sun and their veins showed blue under their pale skin, and “blue-eyed boy,” referring to a favored protégé; this phrase likely stems from the fact that fair-skinned and fair-haired people, who at one time had a social advantage over their swarthier counterparts, are likely to have blue eyes.

Other negative idioms include the use of blue to refer to a sad or bleak mood, as well as “black and blue,” meaning “bruised,” from the color of bruised skin, and “blue in the face,” referring to someone trying (in vain) to persuade another until, from lack of breath, they attain this state.

Purple or Violet

Purple, also called violet, like its color-spectrum counterpart yellow, has little representation in idiomatic language: Purple prose is that which is overwrought or overly complicated, and a shrinking violet is a shy person, though the usage is usually employed in such phrases as “not a shrinking violet” to refer to someone who is anything but shy.

The color purple, because materials for dying fabric in that color were rare and therefore expensive, was reserved for royalty or the wealthy in western cultures and still has an association with nobility. This association resulted in another idiom, “born to the purple,” meaning “someone born to royalty during their reign” and, by extension, referring to children of prominent people.

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6 thoughts on “Idioms Referring to Colors of the Rainbow”

  1. I know that the colours of the spectrum are largely arbitrary definitions, but I was always taught that there were seven. What happened to indigo?

  2. The colors of the spectrum are very specifically defined. The eye perceives a color based upon the wavelength, energy, and other aspects of the light it detects. Red light has the longest wavelength and violet has the shortest. That is why in a rainbow the colors are always in the same order: red, orange, yellow, green, blue, violet.

    Infrared light is not visible by the human eye and its wavelength is longer than red’s. Ultraviolet light — the cause of sunburns — has a wavelength shorter than violet. Shorter yet are microwaves.

    Indigo has a very specific definition, but current science doesn’t include it in the colors of the rainbow. Wikipedia says Isaac Newton first defined the colors of the rainbow, but he did not include indigo or orange. He later added those colors. The current Munsell system (1930s) includes orange but not indigo.

  3. First Pluto gets demoted from its state as a planet, and now indigo is dropped from the spectrum. What is next? Personally, I’ll continue to think there are 9 planets (even though I have no beef with recategorizing Pluto) and will continue to mutter “Roy G. Biv” anytime I’m putting colors in order. Old habits die hard.

  4. And then there are all the political meanings of some of these colors:

    Red State: Republican (and also, curiously, Communist)
    Orange Men: the notoriously Protestant secret Northern Irish society
    Green: Sustainable (or fuel-less) energy, and the well-being associated with it

    Color and Mood:
    Blue: somehow it got missed that this is the name of an emotional state or mood. It is also associated, in ‘the blues,’ with a genre of music loosely attached to being blue.

    Red: ‘Seeing red’ is an idiom for being extremely angry
    Purple: ‘Turning purple’ is an advanced state of ‘seeing red’
    Yellow: The color of hope. Remember all those yellow ribbons after 9/11, and for Iraq War troops?

    Tangentially regarding why yellow might have come to mean cowardice, Roshi Phillip Kapleau, the founder of the Rochester Zen Center and author of “The Three Pillars of Zen,” once said “Silence is golden. But sometimes it’s yellow.”

  5. @Ed Buckner: I am not being facetious when I say your post was erudite. Very interesting. I still miss indigo (and Pluto), and I’m with Danny and our friend “Roy.”
    @Dwain: Excellent addition to the main post, thanks!

    Names of colors have also been used to refer to various people (e.g. red man=native american, yellow man=oriental). And since they’re so awesome, I must mention Blue Man Group! Also, “true blue,” meaning loyal.

    I just want to throw my 2 cents in and say that as long as we’re on the subject of rainbows, a rainbow has been used to represent GLBT (gay/lesbian/bisexual/transgendered) interests, as all-inclusive.

  6. I agree with Stephen in saying that the colors defined as being in the rainbow are somewhat arbitrary — since ALL visible colors are in the rainbow – so yes, the arbitrary part is because sometimes some colors are listed, and other times, other writers, a slightly different set is listed –
    — I prefer to go with The Beatles: “Blue, Green, Yellow, Red, can I bring my friend to bed; Red, Orange, Yellow, Green and Blue, I love you!”
    — OH! and the colors are also in the opposite order …. when you see the double rainbow (and all rainbows are doubles, sometimes the 2nd one just can’t be seen) then the order of colors are opposite in the two rainbows!

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