Red vs. Blue — What's the Difference?
Edited by Tayyaba Rehman — By Fiza Rafique — Updated on November 2, 2023
Red is a warm primary color at the longer-wavelength end of the visible spectrum, while blue is a cool primary color at the shorter-wavelength end.
Difference Between Red and Blue
Table of Contents
ADVERTISEMENT
Key Differences
Red is a primary color, traditionally associated with warmth, passion, and danger. Blue, also primary, is linked to coolness, serenity, and stability. Red wavelengths are longer; blue's are shorter.
Red is often used in warning signs due to its high visibility. Blue, providing a sense of calm, is favored for corporate logos. Red is a color of extremes; blue is viewed as conservative and reliable.
Red is the color of blood and fire, signifying strong emotions like love and anger. Blue is the color of the sky and sea, often associated with depth and stability. Red garners attention; blue soothes.
Red is known to stimulate appetite, explaining its prevalence in restaurant branding. Blue is thought to suppress hunger, and it's often used in diet-related products. Red excites; blue calms.
In politics, red may represent conservative or socialist movements, depending on the context. Blue can symbolize liberal or conservative ideas, varying by region. Red is intense; blue is steady.
ADVERTISEMENT
Comparison Chart
Wavelength
Longer, around 620-750 nm
Shorter, around 450-495 nm
Symbolism
Passion, urgency, warmth
Calmness, stability, coolness
Cultural Significance
Danger, love, revolution
Peace, corporate, loyalty
Use in Branding
Excitement, appetite stimulation
Trustworthiness, relaxation
Political Association
Varied: conservative, socialist
Varied: liberal, conservative
Compare with Definitions
Red
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres.
Blue
Blue is one of the three primary colours of pigments in painting and traditional colour theory, as well as in the RGB colour model. It lies between violet and green on the spectrum of visible light.
Red
The hue of the long-wavelength end of the visible spectrum, evoked in the human observer by radiant energy with wavelengths of approximately 630 to 750 nanometers; any of a group of colors that may vary in lightness and saturation and whose hue resembles that of blood; one of the additive or light primaries; one of the psychological primary hues.
Blue
The hue of that portion of the visible spectrum lying between green and indigo, evoked in the human observer by radiant energy with wavelengths of approximately 420 to 490 nanometers; any of a group of colors that may vary in lightness and saturation, whose hue is that of a clear daytime sky; one of the additive or light primaries; one of the psychological primary hues.
Red
A pigment or dye having a red hue.
Blue
A pigment or dye imparting this hue.
Red
Something that has a red hue.
Blue
Bluing.
Red
Often Red A Communist.
Blue
Dress or clothing of this hue
The ushers wore blue.
Red
A revolutionary activist.
Blue
A person who wears a blue uniform.
Red
Having a color resembling that of blood.
Blue
Blues A dress blue uniform, especially that of the US Army.
Red
Reddish in color or having parts that are reddish in color
A red dog.
A red oak.
Blue
The Union Army.
Red
Having a reddish or coppery skin color.
Blue
A bluefish.
Red
Often Red Often Offensive Of or being a Native American.
Blue
Any of various small blue butterflies of the subfamily Polyommatinae.
Red
Often Red Communist.
Blue
The sky.
Red
Having red#Noun as its color.
The girl wore a red skirt.
Blue
The sea.
Red
(of hair) Having an orange-brown or orange-blond colour; ginger.
Her hair had red highlights.
Blue
Of the color blue.
Red
(of the skin) With a red hue due to embarrassment or sunburn.
Blue
Bluish or having parts that are blue or bluish, as the blue spruce and the blue whale.
Red
Supportive of, related to, or dominated by a political party or movement represented by the color red:
Blue
Having a gray or purplish color, as from cold or contusion.
Red
Indicating financial deficit in business.
The company's accounts are in the red this quarter.
Blue
Wearing blue.
Red
The condition of being in debt or operating at a loss
The firm has been in the red all year.
Blue
Being a trail, as for skiing, marked with a sign having a blue square, indicating an intermediate level of difficulty.
Red
Having a ruddy or flushed complexion
Red with embarrassment.
Blue
A color on the spectrum seen in the sky and ocean.
The clear sky above was a perfect shade of blue.
Red
Relating to or being a red state.
Blue
Often represents sadness or melancholy in expressions.
He felt blue after hearing the unfortunate news.
Red
Of the hearts or diamonds suits. Compare of the spades or clubs suits
I got two red queens, and he got one of the black queens.
Blue
Used to describe a cold or unemotional demeanor.
Her blue demeanor kept people at a distance.
Red
Left-wing parties and movements, chiefly socialist or communist, including the U.K. Labour party and the Social Democratic Party of Germany.
The red-black grand coalition in Germany
Blue
A political color representing different parties worldwide.
The blue posters dominated the political landscape in the city.
Red
(US politics) The U.S. Republican Party.
A red state
A red Congress
Blue
An object having this hue.
Red
Amerind; relating to Amerindians or First Nations
Blue
A member of the Union Army in the Civil War.
Red
(astronomy) Of the lower-frequency region of the (typically visible) part of the electromagnetic spectrum which is relevant in the specific observation.
Blue
Relating to or being a blue state.
Red
(particle physics) Having a color charge of red.
Blue
Gloomy; depressed.
Red
Any of a range of colours having the longest wavelengths, 670 nm, of the visible spectrum; a primary additive colour for transmitted light: the colour obtained by subtracting green and blue from white light using magenta and yellow filters; the colour of blood, ripe strawberries, etc.
Red can be seen as hot or angry.
Blue
Dismal; dreary
A blue day.
Red
(countable) A revolutionary socialist or (most commonly) a Communist; usually capitalized a Bolshevik, a supporter of the Bolsheviks in the Russian Civil War.
Blue
Puritanical; strict.
Red
One of the 15 red balls used in snooker, distinguished from the colours.
Blue
Aristocratic; patrician.
Red
Red wine.
Blue
Indecent; risqué
A blue joke.
A blue movie.
Red
(countable) Any of several varieties of ale which are brewed with red or kilned malt, giving the beer a red colour.
Blue
To make or become blue.
Red
A red kangaroo.
Blue
Having blue as its color.
The deep blue sea
Red
A redshank.
Blue
(informal) Depressed, melancholic, sad.
Red
An American Indian.
Blue
(health care) Having a bluish or purplish shade of the skin due to a lack of oxygen to the normally deep red blood cells.
The divers got them out of the car just in time – they were starting to turn blue.
Red
(slang) The drug secobarbital; a capsule of this drug.
Blue
Pale, without redness or glare; said of a flame.
The candle burns blue.
Red
(informal) A red light a traffic signal
Blue
(politics) Supportive of, run by (a member of), pertaining to, or dominated by a political party represented by the colour blue.
Red
(particle physics) One of the three color charges for quarks.
Blue
Supportive of, run by (a member of), pertaining to, or dominated by the Democratic Party.
I live in a blue constituency.
Congress turned blue in the mid-term elections.
Red
Usually in the phrase "bowl of red".
Blue
Supportive of or related to the Liberal Party.
Illawarra turns blue in Liberal washout
Red
(informal) The redfish or red drum, Sciaenops ocellatus, a fish with reddish fins and scales.
Blue
(UK politics) Supportive of or related to the Conservative Party.
Red
Tomato ketchup.
Blue
(astronomy) Of the higher-frequency region of the part of the electromagnetic spectrum which is relevant in the specific observation.
Red
(archaic) rede
Blue
(of steak) Extra rare; left very raw and cold.
Red
To put on order; to make tidy; also, to free from entanglement or embarrassement; - generally with up; as, to red up a house.
Blue
(of a dog or cat) Having a coat of fur of a slaty gray shade.
Red
Of the color of blood, or of a tint resembling that color; of the hue of that part of the rainbow, or of the solar spectrum, which is furthest from the violet part.
Your color, I warrant you, is as red as any rose.
Blue
(archaic) Severe or overly strict in morals; gloomy.
Blue and sour religionists;
Blue laws
Red
The color of blood, or of that part of the spectrum farthest from violet, or a tint resembling these.
Blue
Literary; bluestockinged.
Red
A red pigment.
Blue
(particle physics) Having a color charge of blue.
Red
The menses.
Blue
(informal) Risqué; obscene; profane; pornographic.
His material is too blue for prime-time
The air was blue with oaths.
A blue movie
Red
The quality or state of the chromatic color resembling the hue of blood
Blue
The colour of the clear sky or the deep sea, between green and purple in the visible spectrum, and one of the primary additive colours for transmitted light; the colour obtained by subtracting red and green from white light using magenta and cyan filters; or any colour resembling this.
Red
A tributary of the Mississippi River that flows eastward from Texas along the southern boundary of Oklahoma and through Louisiana
Blue
Anything coloured blue, especially to distinguish it from similar objects differing only in color.
I don't like red Smarties. Have you got a blue?
Red
Emotionally charged terms used to refer to extreme radicals or revolutionaries
Blue
A blue dye or pigment.
Red
The amount by which the cost of a business exceeds its revenue;
The company operated at a loss last year
The company operated in the red last year
Blue
Blue clothing.
The boys in blue marched to the pipers.
Red
Having any of numerous bright or strong colors reminiscent of the color of blood or cherries or tomatoes or rubies
Blue
(in the plural) A blue uniform. See blues.
Red
Characterized by violence or bloodshed;
Writes of crimson deeds and barbaric days
Fann'd by Conquest's crimson wing
Convulsed with red rage
Blue
A member of a sports team that wears blue colours; (in the plural) a nickname for the team as a whole. See also blues.
Come on you blues!
Red
(especially of the face) reddened or suffused with or as if with blood from emotion or exertion;
Crimson with fury
Turned red from exertion
With puffy reddened eyes
Red-faced and violent
Flushed (or crimson) with embarrassment
Blue
An umpire, in reference to the typical dark blue color of the umpire's uniform. Sometimes perceived by umpires as derogatory when used by players or coaches while disputing a call.
He was safe! Terrible call, blue!
Red
Red with or characterized by blood;
Waving our red weapons o'er our heads
The Red Badge of Courage
The red rules of tooth and claw
Blue
Sporting colours awarded by a university or other institution for sporting achievement, such as representing one's university, especially and originally at Oxford and Cambridge Universities in England. See also full blue, half blue.
He excelled at rowing and received a blue in the sport at Oxford.
Red
A color at the end of the visible spectrum of light.
The red apple looked ripe and delicious.
Blue
A person who has received such sporting colours.
He was a blue in rugby at Cambridge.
Red
A symbol of danger or stop in traffic signals.
The car halted as the traffic light turned red.
Blue
(slang) A member of law enforcement.
Red
Often associated with passion or strong emotions.
She wore a red dress to signify her fiery personality.
Blue
A bluestocking.
Red
A political color used to represent certain ideologies.
The red flags were raised during the rally.
Blue
The sky, literally or figuratively.
The balloon floated up into the blue.
His request for leave came out of the blue.
Blue
The ocean; deep waters.
Blue
The far distance; a remote or distant place.
Blue
A dog or cat with a slaty gray coat.
Blue
(snooker) One of the colour balls used in snooker, with a value of five points.
Blue
(entomology) Any of the butterflies of the subfamily Polyommatinae in the family Lycaenidae, most of which have blue on their wings.
Blue
A bluefish.
Blue
An argument.
Blue
A liquid with an intense blue colour, added to a laundry wash to prevent yellowing of white clothes.
Blue
Any of several processes to protect metal against rust.
Blue
(British) A type of firecracker.
Blue
(particle physics) One of the three color charges for quarks.
Blue
(UK) A member or supporter of the Conservative Party.
He is a true blue.
Blue
(ergative) To make or become blue; to turn blue.
Blue
To treat the surface of steel so that it is passivated chemically and becomes more resistant to rust.
Blue
To brighten by treating with blue (laundry aid).
Blue
To fight, brawl, or argue.
Blue
To spend (money) extravagantly; to blow.
Blue
Having the color of the clear sky, or a hue resembling it, whether lighter or darker; as, the deep, blue sea; as blue as a sapphire; blue violets.
Blue
Pale, without redness or glare, - said of a flame; hence, of the color of burning brimstone, betokening the presence of ghosts or devils; as, the candle burns blue; the air was blue with oaths.
Blue
Low in spirits; melancholy; as, to feel blue.
Blue
Suited to produce low spirits; gloomy in prospect; as, thongs looked blue.
Blue
Severe or over strict in morals; gloom; as, blue and sour religionists; suiting one who is over strict in morals; inculcating an impracticable, severe, or gloomy mortality; as, blue laws.
Blue
Literary; - applied to women; - an abbreviation of bluestocking.
The ladies were very blue and well informed.
For his religion . . . 'T was Presbyterian, true blue.
Blue
One of the seven colors into which the rays of light divide themselves, when refracted through a glass prism; the color of the clear sky, or a color resembling that, whether lighter or darker; a pigment having such color.
Blue
A pedantic woman; a bluestocking.
Blue
Low spirits; a fit of despondency; melancholy.
Blue
To make blue; to dye of a blue color; to make blue by heating, as metals, etc.
Blue
The color of the clear sky in the daytime;
He had eyes of bright blue
Blue
Blue clothing;
She was wearing blue
Blue
Any organization or party whose uniforms or badges are blue;
The Union army was a vast blue
Blue
The sky as viewed during daylight;
He shot an arrow into the blue
Blue
Used to whiten laundry or hair or give it a bluish tinge
Blue
The sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic
Blue
Any of numerous small chiefly blue butterflies of the family Lycaenidae
Blue
Turn blue
Blue
Having a color similar to that of a clear unclouded sky;
October's bright blue weather
A blue flame
Blue haze of tobacco smoke
Blue
Used to signify the Union forces in the Civil War (who wore blue uniforms);
A ragged blue line
Blue
Low in spirits;
Lonely and blue in a strange city
Depressed by the loss of his job
A dispirited and resigned expression on her face
Downcast after his defeat
Feeling discouraged and downhearted
Blue
Characterized by profanity or cursing;
Foul-mouthed and blasphemous
Blue language
Profane words
Blue
Suggestive of sexual impropriety;
A blue movie
Blue jokes
He skips asterisks and gives you the gamy details
A juicy scandal
A naughty wink
Naughty words
Racy anecdotes
A risque story
Spicy gossip
Blue
Belonging to or characteristic of the nobility or aristocracy;
An aristocratic family
Aristocratic Bostonians
Aristocratic government
A blue family
Blue blood
The blue-blooded aristocracy
Of gentle blood
Patrician landholders of the American South
Aristocratic bearing
Aristocratic features
Patrician tastes
Blue
Morally rigorous and strict;
Blue laws
The puritan work ethic
Puritanic distaste for alcohol
She was anything but puritanical in her behavior
Blue
Causing dejection;
A blue day
The dark days of the war
A week of rainy depressing weather
A disconsolate winter landscape
The first dismal dispiriting days of November
A dark gloomy day
Grim rainy weather
Blue
A term for a genre of music known as the blues.
The guitar player was famous for his blue notes.
Common Curiosities
Is red a warm or cool color?
Red is considered a warm color.
How is blue perceived in color psychology?
Blue is perceived as calm, stable, and trustworthy in color psychology.
Why is red used for stop signals?
Red is highly visible and universally associated with alertness and caution.
What does feeling blue mean?
Feeling blue is an idiom that means feeling sad or depressed.
What's a blue moon?
A blue moon refers to the second full moon in a calendar month, not color.
Are there any countries that feature both red and blue in their flags?
Yes, numerous countries, including the United States, feature both colors in their flags.
Are red and blue used differently in art?
Yes, artists use red to draw attention and blue to create depth and perspective.
Can red and blue be mixed to form other colors?
Yes, when combined, red and blue create purple.
What does being "in the red" financially mean?
It means to be in debt or losing money.
Do red and blue have opposite meanings in politics?
Yes, often red and blue represent opposing political ideologies.
What emotions are typically associated with red?
Red is often associated with passion, excitement, and danger.
Does red light have a longer wavelength than blue light?
Yes, red light has a longer wavelength compared to blue light.
Is blue a primary or secondary color?
Blue is a primary color.
In terms of temperature, what do red and blue indicate?
Red often indicates warmer temperatures, while blue indicates cooler temperatures.
Why is blue commonly used in corporate logos?
Blue conveys professionalism, reliability, and trustworthiness.
Share Your Discovery
Previous Comparison
Everytime vs. Whenever
Next Comparison
Element vs. MoleculeAuthor Spotlight
Written by
Fiza RafiqueFiza Rafique is a skilled content writer at AskDifference.com, where she meticulously refines and enhances written pieces. Drawing from her vast editorial expertise, Fiza ensures clarity, accuracy, and precision in every article. Passionate about language, she continually seeks to elevate the quality of content for readers worldwide.
Edited by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.
