Red is a color at the lowest frequencies of light discernible by the human eye. Red light has a wavelength range of roughly 1 E-7 mNanometer.
Red is an additive primary color, complementary to cyan. It was once considered to be a subtractive primary color, and is still sometimes described as such in non-scientific literature; however, the colors cyan, magenta and yellow are now known to be closer to the true subtractive primary colors detected by the eye, and are used in modern color printing.
Lower frequencies are called infrared, or ''far red''.
A red filter (photography) used in black and whitephotography increases contrast in most scenes. For example, combined with a polarizer, it can turn the sky black. Films simulating the effects of infrared film (such as Ilford's SFX 200) do so by being much more sensitive to red than to other colors.
Oxygenated blood is red due to the presence of hemoglobin. Red light is the first to be absorbed by sea water, so that many fish and marine invertebrates that appear bright red are black in their native habitat.
== Usage, symbolism, colloquial expressions ==
* Red is the color of warmth, for instance used to indicate warmer areas on a weather map, or for heat-related warnings.
* Red catches people's attention, and is often used to indicate danger or emergency.
** Red is the color of heat and fire. Tap (valve)s for hot water are often labeled red. Red is commonly the color of fire alarm boxes, fire extinguishers, and the firefighter profession itself.
** Red denotes "stop" in, for instance, stop signs, traffic light, brake lights, or the flashing lights of a school bus.
**A Red Cross signify medical personnel, facilities, or equipment, or the Geneva conventions.
** Red indicates extreme danger on Western color-coded scales, such as wildfire hazard signs or the U.S. Homeland Security Advisory System.
** In auto racing, a red flag signals all cars to immediately stop. The redline is the maximum speed an engine and its components can run.
** Emergency exits on passenger aircraft are indicated by red signs and lighting.
** "Redlining" is delineating a forbidden area (as on a map), for instance where a company denies or increases the cost of services, and is illegal in various circumstances in the U.S.
*In religion, Red also represents the color of fire and so symbolizes the presence of God. It is the Liturgy color for Pentecost. It is also considered the color of the Church, since red can also symbolize the blood of martyrs. It is sometimes used for Maundy Thursday and during Eastertide. In Catholic tradition it is used for Palm Sunday in anticipation of the death of Jesus.
* In football (soccer), the referee (football) shows a red card to a player who is being sent-off.
* Red is the color of both romantic and carnal love, thus the red of a valentine heart and of a "red-light district". But it may also denote anger, as in the expression ''seeing red'', or embarrassment, as in being ''red-faced''.
*Being the color of blood, red was associated with the god of war, Mars (god), and the reddish planet Mars (planet) became named after him. The phrase "red-blooded" describes someone who is audacious, robust, or virile; it is sometimes used to contrast with a cold or effete "blue blood" although the terms are unrelated in origin.
* Before the French revolution red was the colour of the flag signifying the imposition of martial law.
* Beginning with the Revolution of 1848, "Socialist" red was used as a color of European Revolution, often in the form of the red flag. It was also used by Giuseppe Garibaldi's ''camicie rosse'' ("redshirts") in the Italian Risorgimento, and taken up by Left-wing politics and generally radical groups, while the white of legitimist House of Bourbon partisans became associated with pre-World War Iconservatives.
** For instance the Russian Civil War and the Civil War in Finland were fought between the "Red Army" and various "White Armies".
** The identification of Communism with "Socialist" red (with the red flag being the primary color of the flag of the Soviet Union) and the red star being a Communist emblem led to such Cold War phrases as "the Red Menace" and "People's Republic of China" (distinguished from Republic of China, "Free China," or ''Taiwan''). The colour was also associated with political vehicles such as the Red Guards (China) in China and the Red Guards (Russia)s during the Russian Revolution as well as with left wing paramilitary groups such as the Red Army Faction in Germany and the Japanese Red Army. .
** Red remains associated with parties on the left of the political spectrum, with several notable exceptions (see "Political Parties" below)
* In Chinese symbolism, red is the color of good luck and is used for decoration and wedding attire. Money in Chinese societies is traditionally given in hong bao. See also The East is Red. Mao Zedong was sometimes referred to as a "red sun".
* In English heraldry, red denoted ardent affection or love, while crimson (blood-color) stood for boldness, enthusiasm, or impetuousity. (The American Girls Handy Book, p. 369-370)
* Red ink is also used to denote debt - as well as losses on a balance sheet (hence the phrase, ''"in the red"'' usually indicates economic losses).
* In North American stock markets, red is used to denote a drop in stock prices. In East Asian stock markets, red is used to denote a rise in stock prices.
* In maps of political parties, red is traditionally used for the following parties:
**Australia: Australian Labor Party
**Canada: Liberal Party of Canada
**Germany: Social Democratic Party of Germany and Party of Democratic Socialism
**The Netherlands: Partij van de Arbeid (Socialist party)
**United Kingdom: Labour Party (UK)
**United States: United States Republican Party, hence states that vote Republican are referred to as red states as opposed to blue states which vote for the United States Democratic Party.
* Red is one of the Christmas colors, with green, white, or both.
* Red, along with yellow and orange, is thought to provoke hunger, hence its use in logos by food vendors.
* In the history of Japan red is the color of military flags used by the Heike (or Taira) clan and of the Genji (or Minamoto) clan, two clans that struggled for power at the close of the History of Japan, in the late 12th century.
* ''Three Colors: Red'' is the last film in the ''Three Colors'' trilogy by Krzysztof Kieslowski.
* Red is the color ''claimed'' by the street gangs Bloods and Norteño (gang)s.
* Red is the word for a fish of the genus ''Myripristis'' in Tobian language.
* ''Red_(album)'' is an album by progressive rock band King Crimson.
* Red is the color of the lowest-value balls in snooker. There are 15 at the beginning of a game, each worth 1 point.
*''Red Indians'' is a British term for Native Americans.
== Variations ==
* Scarlet (color) - a shade of red that tends towards red-orange (color) and has no hint of blue
* Vermilion - a fiery shade of red that tends toward red-orange to a silghtly greater degree than scarlet, prepared from cinnabar, the artificial red sulphide of Mercury (element) used as a pigment
* Pink - a very light, unsaturated red, traditionally the color of Dianthus
* Maroon (color) - a deep, dark, brownish (desaturated) red
* Venetian Red (also known as India Red or Indian Red) - A shade of brownish red prepared from sulphate of iron.
* Carmine - a dark, blue-tinged red traditionally the color of a dye made from the cochineal insect
* Rose (color) is a range of colors on the blue side of red
**''Damask'' specifically refers to the color of the Damask rose.
* Crimson - a shade of red that has no hint of yellow and leans towards red-violet
* Cardinal (color) - a vivid red
* Cerise (color) - another dark blue-red
* "Fire Engine Red" - an intense red commonly used on emergency vehicles
* "Jungle Red" was the nail polish color in ''The Women''.
* Peach (color) is a range of colors on the yellow side of red and generally tending toward a light tint.
* Burgundy - another dark, sometimes grayish violet-red
== See also ==
*List of colorsColorsOptical spectrumscn:Russusimple:Redsu:Beureumth:สีแดงvi:Đỏ
Red
I moved the following sentence from the main article here:
:''In fact, both blood and the planet Mars get their reddish hue from oxidized iron (rust).''
I am not sure this is correct. First of all, hemoglobin is red whether it contains oxygen or not. Second, if it contains oxygen, then it contains molecular oxygen (O2) and not oxydized iron. Could somebody with a firmer grasp on these things please confirm? --user:AxelBoldt
----
Yeah I think this is correct. Oxygen is bound to the Haem groups in haemoglobin chains to form oxyhaemoglobin (HbO8:
Hb + 4O2 -> HbO8
Although 'oxidized' may not be so chemically correct (I don't know about loss of electrons) they are loosely bound and not in the 02 form.
----
Do you think the original statement, claiming that blood is red because of oxidized iron, is correct, or that my statement above is correct? --user:AxelBoldt
----
original statemen -- sodium
----
Well, I don't understand your argument. What are you claiming actually causes the red colour of haemoglobin? As far as I know, haematite is red because of the Fe3+ ions. Haemoglobin (both oxy- and deoxy-) has Fe2+ ions - the iron is not oxidized by the binding of oxygen. Fe2+ ions cause a yellow-green colour, I think, so they can't be what makes haemoglobin red. Unless I've got something wrong here, the original statement is at best very misleading. --user:Zundark, 2001 Oct 8
The color of an ion depends on its environment. In aqueous solution ferric irons (Fe3+) are coordinated with six water molecules and have a yellow color rather than the reddish color of hematite, where they are coordinated with six oxide ions, while the anhydrous chloride is greenish. Fe2+ are green in aqueous solution but that doesn't say much, the presence of nitrogen and oxygen (only oxyhemoglobin is bright red) are going to affect the color significantly. The iron is definitely what is responsible, though, and most brightly colored compounds are made so by coordinated transition metals. Someday we should have an article on :ligand field theory.
----
How about the following statement:
:"Both the red color of Mars and the red color of blood are caused by an interaction of oxygen and iron."
That avoids the term "oxidization" which is not involved in hemoglobin if I understand it correctly. --user:AxelBoldt
----
Have some questions about this statement
In most if not all human languages, "red" is the first color name
developed after "black" and "white."
I'm not sure what this means. Does it mean that ten thousand years ago,
people only talked about black and white and then someone invented the
word red? Or does it mean that babies learn to identify red after they
identify black and white.
It's not obvious to me that we know enough about the development
of language to make the first statement. If the second is true they
it should be expanded.
::Here's the story. I don't have a citation right wth me, but it's a fairly standard linguistic thing. A survey of a large number of languages revealed the following:
::-All languages had terms for black and white.
::-If a language had three terms, it had a term for red.
::-If a language had four terms, it had a term for either yellow or green.
::-If a language had five terms, it had terms for both yellow and green.
::-If a language had six terms, it had a term for blue.
::And so forth. I'll try to get a cite and expand on it - it could be an article. - user:Montrealais
:::So red is just a color people tend to notice, (I think Red is one of the most noticable colors.) and then name. Its sensible from an evolutionary standpoint, blood is red (well, bleeding blood, anyway) and if blood is bleeding that's something generally beneficial to notice.
----
Although it's true that red is traditionally the color used on maps for the U.S. Republican party, it seems inconsistent to say this when the maps featured on Wikipedia use red for Democrats. Media:Image:ElectoralCollege2000.png I'm not sure how/if I should add this to the article, though, so I'm just tossing it out there. User:Rebrane
== RGB coordinates for Red ==
What RGB coordinates do you think sound more natural to call "pure red"?? The reason most people like to say 255 0 0 is because of the R that stands for red. However, 255 0 128 is actually pure red, defining it as red that is totally neutral on the blue-yellow scale (the scale that defines blue and yellow.) Practice this:
Go to Microsoft PowerPoint. Upon seeing the first slide, edit the colors so that the background has RGB coordinates of 255 0 128. Then, draw a rectangle or oval and make the coordinates 255 0 0. Then, set the line settings for the rectangle and oval so that there is no line. You will see that the rectangle or oval is actually somewhat orange-ish and that the background is more pure red.
There is another version of this, which is to replace "red" with "green", "255 0" as the first 2 RGB coordinates with "0 255", and "orange-ish" with "lime-ish".
== Now it says... ==
"The RGB coordinates of red are 255 0 0. Note that the red phosphor on CRT-based computer displays is slightly yellowish compared to a "peak" pure spectral red color: see metamerism."
True or false: the "peak" pure spectral red color is 255 0 128??
: False, is defined as the color red on a monitor. If your monitor doesn't manage to show red at (255, 0, 0), you should recalibrate your monitor. Try adjusting the "color temperature" settings specifically. Photoshop has some excellent monitor calibration tools as well. User:Kim Bruning 21:05, 3 Apr 2004 (UTC)
A discussion of metamerism wrt. CMYK might have been interesting, but it is not relevant to the RGB colorspace, since RGB is used for light sources themselves. Since I'd put in a nicer colorspace block, we can delete the paragraph entirely. User:Kim Bruning 21:15, 3 Apr 2004 (UTC)
== Please answer ==
# What are the RGB coordinates of crimson??
: (220,20,60) make a good crimson, if crimson is correct.
You could have calculated that yourself, just looking at that page source.
# What are the RGB coordinates of scarlet??
User:66.32.126.20 21:16, 3 Apr 2004 (UTC)
: Dunno, scarlet isn't defined on wikipedia, not at the moment at least. If you tell me what colors make up scarlet, I can probably tell you the right numbers. That or make yourself a user page, put where that page is on my talk, and I'll make you a sandpit so you can experiment with colors yourself. Will that too?
User:Kim Bruning 21:21, 3 Apr 2004 (UTC)
* Yes, "scarlet" is mentioned at Wikipedia at the main red page. User:66.32.126.20 21:23, 3 Apr 2004 (UTC)
: Seen it. I'm going to guess at (255,127,0) which should get you pretty close.
Use one of the many tools I have mentioned to you now to confirm that, or find a better scarlet. Do first make sure that your monitor is corectly calibrated.
User:Kim Bruning 21:30, 3 Apr 2004 (UTC)
==List of terms associated with the color red==
*anger
*blood
*Christmas
*energy
*enthusiasm
*fire
*hate
*heat
*lava
*leadership
*love
*Mars (planet)
*masculinity
*passion
*power
*strength
At least some of these should be merged into this article. User:Anthony DiPierroUser:Anthony_DiPierro/warning 22:31, 16 Oct 2004 (UTC)
user
== "Red" and "read" ==
:''The term "red" has also come to stand for an abbreviation of the word "read" and is being used as such by the current generation of high school and college students. The increasing popularity of what is now being referred to as "internet slang" furthermore provides for the possibility that use of the word "red" in place of "read" may become commonplace within the next few years.''
What? I've never witnessed this. Nor have I heard about it. Nor red about it. ... ... D'oh! - User:Furrykef (User_talk:Furrykef) 08:45, 4 Feb 2005 (UTC)
Red
Interests:
* Medicine
* Literature
* Other stuff
To do:
* Anton's Syndrome
Red
{}
Red
Wikipedia:Red links mean an article does not exist. Please do not mislead people by using this confusing template to make links red when they should not be. I've removed it from Template:Cleanup. User:Angelauser talk:Angela 03:02, Aug 8, 2004 (UTC)