Talk:Impossible color

Color response curve misleading
I believe this plot is misleading in two ways:

First, it claims to be adapted from [http://psy2.ucsd.edu/~dmacleod/publications/61StockmanMacLeodJohnson1993.pdf Stockman et al. Vol. 10, No. 12/December 1993/J. Opt. Soc. Am. A 2491]). However, it would appear the adaptation was not sufficiently careful, as it missed the UV behavior, see figure 12 in above reference.

Second, and more importantly, it does not accurately reflect reality, and fails to account for the following phenomena: We know the shortest wavelength on the rainbow appears purple, as does and equal combination of red + blue (RGB 128,0,128). This is inconsistent with the above plot.

Instead, see discussion on StackExchange. The correct plot should be http://i.stack.imgur.com/z3dtf.png, which is referenced to [http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.1980.sp013097/pdf Bowmaker, J.K., & Dartnall, H.J.A. Visual pigments of rods and cones in a human retina. Journal of Physiology, 298, 1980, 501-511] figure 2, as it allows us to understand how an RGB-based screen can generate a color which appears as purple. — Preceding unsigned comment added by Shai mach (talk • contribs) 08:55, 6 December 2015 (UTC)


 * violet as seen in a rainbow and magenta (blue and red light mixing), are two visually different colors. "Purple" is largely meaningless as it's often confused for both violet and magenta and has a rather wide range of definiton. Magenta does not appear in a rainbow.

Queries
I'm a vision scientist and felt it was important to correct the content of this article. The way it was worded made it appear as if impossible colors were a well established phenomenon. While there are cases of synesthetes who see 'martian' colors, there is no conclusive evidence that a normal person will see them ... especially in the given paradigm of binocular rivalry. —Preceding unsigned comment added by Zuchinni one (talk • contribs) 03:17, 7 May 2010 (UTC)


 * This article sites no sources. It also reads like an argument between editors.  I would fix it up but I don't know anything about the subject and I don't know how to put in those cool "citation needed" tags.--216.31.211.11 (talk) 06:18, 9 May 2010 (UTC)


 * The tags are easy, just type cn after the passage you wish to tag. Perhaps user Zuchinni one can provide some references, they seem to be an expert.  Sp in ni  ng  Spark  09:26, 9 May 2010 (UTC)


 * I'm also a color scientist, and would like to reinforce that this is a controversial page. If it was in Wztezeki and Styles Color Science it would be law, but it is not. 24.34.116.51 (talk) 00:08, 1 March 2011 (UTC)Anon


 * It does seem to need some editing. The last paragraph in the 'Claimed Evidence' section reads as though it's written purely to rubbish the preceding work. And it's uncited. 86.155.172.22 (talk) 15:15, 21 April 2011 (UTC)


 * I think the editor who put it in (Zuchinni, who started this thread) is used to writing in a more scholarly setting and was reluctant to edit the work of others. Consequently, he/she has phrased it as a counterargument to what is already there.  Fwiw, I think Zuchinni is correct.  By the way, it is not true that no sources are cited, the one and only sentence I put in has an inline cite and the original article is clearly referenced to the work cited in the ref section (but not inline).  Sp in ni  ng  Spark  18:53, 21 April 2011 (UTC)


 * I think this link will help with refs. http://en.wikipedia.org/wiki/Opponent_process#Reddish_green_and_yellowish_blue --174.71.78.253 (talk) 13:18, 8 May 2011 (UTC)

"Cones and Rods"?
In the section "Opponent process", this article says "The color opponent process is a color theory that states that the human visual system interprets information about color by processing signals from cones and rods in an antagonistic manner." This is also the lede sentence in the article Opponent process. Should "and rods" be deleted from this sentence? Duoduoduo (talk) 17:28, 9 June 2011 (UTC)
 * I think not, because the opponent process theory also integrates black and white into the system as colors.  — Soap  —  18:11, 9 June 2011 (UTC)


 * But black and white are cone colors: white is an equal mixture of all frequencies with high luminescence, while black is achieved in the limit as the luminescence is lowered. So the issue is: do the sources say anything about rods? Duoduoduo (talk) 18:57, 9 June 2011 (UTC)


 * Black and white aren't cone colors per se (white arguably is but eh). Rods are the predominant cell used in low light vision, and perception of grey and blacks are the response. This is traditionally not considered color vision, but when when including variants of grey, rods have to be taken into consideration. — Preceding unsigned comment added by 144.121.8.162 (talk) 15:12, 31 January 2018 (UTC)

In my experience

 * I have seen reddish-green, by exposing one eye to red and one eye to green. Similarly with yellowish-blue.
 * See this search for statements that various real plant parts are reddish-green.
 * At Jodrell Bank several years ago I once saw a reddish-green hedge: as I got closer the reddish-green broke up into green leaves and reddish bark which had been at about the same apparent size as the natural pixel size in my eyes' retinas. Reddish-green from this cause may cause some of the "indescribable autumn russets" which painters have difficulty reproducing. Anthony Appleyard (talk) 10:22, 23 November 2011 (UTC)
 * With crossed eyes I only see the two color patches fighting with each other (sometimes I see the blue, sometimes the yellow, but not a third color, the same is true for non-opposing colors.) Calmarius (talk) 15:24, 12 April 2013 (UTC)
 * In a stereoscope I once saw a Transformers cartoon image including the glowing energy substance energon, and it showed the energon as yellow to one eye and red to the other eye, causing a peculiar effect. Anthony Appleyard (talk) 23:58, 20 November 2014 (UTC)
 * Anyone who's tied psychedelics has likely seen plenty of impossible colors. Saturation in colors that shouldn't be possible, off purples and greens that do not exist through any combination of light. — Preceding unsigned comment added by 144.121.8.162 (talk) 14:57, 31 January 2018 (UTC)

More Experience
Yellowish-blue is not an impossible colour - its called "green". Yellowish red is called "orange". Greenish red is not impossible - its called either brown, ochre, khaki, gambodge, umber, tuscan red, or a few other names depending on the relative proportions of red and green. I have normal colour vision (to prevent any objections on those grounds). Barney Bruchstein (talk) 18:34, 5 June 2013 (UTC)
 * I think you're confusing blending with color perception. Green is not a yellowish blue or a blue-ish yellow. Just consider the difference in perception between a pure green and a yellowish green or blueish green and how they differ from green compared to how green differs from blue or yellow. — Preceding unsigned comment added by 144.121.8.162 (talk) 14:51, 31 January 2018 (UTC)

Imagine a color you can't even imagine.

 * Now do that nine more times. That is how the mantis shrimp do. Hellbus (talk) 03:36, 19 November 2014 (UTC)
 * actually, this term refers to colors that appear to impossibly blend two "possible" colors. i think your time (and ze frank references) would be better spent at imaginary color, or polarization and ultraviolet, which are the extra types of light the mantis shrimp can see. ~ Boomur &#91;☎&#93; 16:45, 19 November 2014 (UTC)
 * Page Imaginary color has been text-merged into page Impossible colors, and page Polarization is a long disambig page. Anthony Appleyard (talk) 09:15, 24 November 2014 (UTC)
 * sorry, i was not as thorough as i normally would have been because my reply was something of a joke. at the time of writing my reply, imaginary color was a separate page, and i was referring to Polarization (waves), which is, of course, the type of polarization relevant to the mantis shrimp. ~ Boomur &#91;☎&#93; 16:44, 24 November 2014 (UTC)


 * Obviously not enough people have watched the video "True Facts About the Mantis Shrimp." Hellbus (talk) 01:07, 8 December 2014 (UTC)

Request move to Impossible color

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section. 

The result of the move request was: move the page, per the discussion below. Dekimasu よ! 02:17, 27 November 2014 (UTC)

Impossible colors → Impossible color – There is no reason to pluralize per WP:PLURAL. Using the singular would make the article match other articles about types of color, such as Primary color, Secondary color, and Imaginary color. I cannot perform the move myself because the redirect has a history. ~ Boomur &#91;☎&#93; 00:26, 20 November 2014 (UTC)


 * Support per nom. Dicklyon (talk) 05:48, 20 November 2014 (UTC)
 * Support – Consistency is good. (Though you should note that Imaginary color is just a redirect to the current article.) --V2Blast (talk) 09:36, 22 November 2014 (UTC)
 * Imaginary color was a separate article when the nomination was made, but apparently it was merged into this one shortly afterward. ~ Boomur &#91;☎&#93; 15:36, 22 November 2014 (UTC)
 * Ah. Makes sense. --V2Blast (talk) 05:16, 24 November 2014 (UTC)


 * Support for consistency. Stickee (talk) 12:58, 22 November 2014 (UTC)


 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

"Opponent process" is poorly integrated into article
Opponent process, which is currently the first section after the Introduction, is not mentioned in the Introduction nor for another two sections, until the third section following it: Chimerical colors. At the same time, the phrase "impossible colors" does not occur at all in the "Opponent process" section.

As a result, the "Opponent process" section appears to have no connection with the article until one reads the third section following it. Instead, this section ought to be integrated better into the article.Daqu (talk) 19:25, 30 December 2014 (UTC)

What about the color perception of dichromates and monochromates?
People who are missing one or two of the three kinds of cone cells perceive colors that others cannot, since every humanly perceivable color normally stimulates all three types of cones, at least somewhat. I do not know much about this, but I hope someone who does will please add a section about normally "impossible" colors that color-blind people can perceive.Daqu (talk) 19:29, 30 December 2014 (UTC)

More than one type of imaginary color?
The article currently says: "One type of imaginary color (also referred to as non-physical or unrealizable color) is a point in a color space that corresponds to combinations of cone cell responses in one eye, that cannot be produced by the eye in normal circumstances seeing any possible light spectrum. ..." This suggests that there are more than one type of imaginary color. What are the other types? SharkD  Talk  22:51, 28 March 2017 (UTC)

Unclear concepts
The article mentions at least 6 different concepts that apparently are all impossible colors:
 * impossible color
 * forbidden color
 * non-physical color
 * unrealizable color
 * chimerical color
 * imaginary color

The relationship between these concepts are not clear from the article.

At one point (the first parenthesis in the first paragraph, which is supposed to list synonyms) the article claims that


 * impossible color = forbidden color = non-physical color = unrealizable color.

But in the "Types" section, it claims that


 * impossible color consists of exactly two subtypes: forbidden color and chimerical color.

Later it claims that


 * imaginary color consists of several subtypes.

It mentions only one subtype,


 * non-physical color = unrealizable color.

It doesn't mention the other claimed subtypes.

Also, I cannot find the place where the article says that an imaginary color is either a type of or a synonym for impossible color. I might be wrong, as the section about "Real colors", where the concept of imaginary color is introduced, is difficult to understand, but I can't find a direct claim that imaginary color is either a subtype of impossible color or a synonym for it.

The section "Chimeral color" states that


 * chimerical color is a subtype of imaginary color.

This contradicts the claim from "Types", in which chimerical color is claimed to be one of only two subtypes of impossible color — unless imaginary color is in fact a direct synonym for impossible color.

I am totally confused.

Could someone who has a full understanding of the concepts and their relationships make the relationships totally clear? I cannot do it myself, as I am totally confused about the relationships.

Please remember that we are writing to people with no knowledge of the subject (such as yours truly), so it's important to state explicitly and unambiguously what a person knowledgable on the subject would find obvious. --Jhertel (talk) 16:27, 8 February 2020 (UTC)


 * You're very right, in for example your last paragraph. And that paragraph is very useful as a 'clear and present' statement of what we should be trying to achieve.
 * The topic is important, too. Understanding of color is an important thread running through the history of science.  It lies on the interface between nature and observer.  It illustrates both progress and problems.
 * I have a feeling tht we'll find it hard to locate any source tht authoritatively relates the different concepts explored, and/or the different phrases used. As the startlng-point, there are differing theories about what color is, and of what colors are possible.  The theories all have their limitations - and/or inadequacies.  Some are little more than mnemonics to help mixing pigments, but are taught in Art or Printing courses as The Scientific Explanation.  I suspect the history of "impossible color" z tht different people at different times have encountered the unexplained puzzles of whatever Explanation they were taught; and they've thought rather hard, and extended that Explanation, to deal with one or another sort of "impossible color" - and the different extensions really don't fit together.  They're based on Explanations tht didn't agree in the first place.
 * We might have to write a section tht says there are different color theories, open to different criticisms; some of the theories predict colors which can't ever be observed in reality; and a whole range of different terms have been applied to these "impossible" colors. Then each theory can be linked, in its own article, and the associated "impossible" colors described in this article, together with references + noting the terminology used in them.
 * A complication z tht some colors can't exist in reality - but can be perceived / 'seen', by doing strange and experimental things to the human vision system. That's another source of the concept of "impossible color".
 * The work you've done listing the terms used will be very helpful in doing all that.
 * -'' SquisherDa (talk) 11:31, 9 February 2020 (UTC)
 * I agree with what you say, and thanks for your kind words.
 * As I hinted, I have almost no knowledge of this area and just came here to inform myself a little bit about it (after first hearing about the concept on QI), but I was left in total confusion. I guess I can't be of much help, as what I'm best at is to make the ambiguous more unambiguous and clear, but I can only do that if I really do grasp what there is an attempt of saying. So my comment just tried to express what I as an unknowledgable reader (on this subject) experienced when reading the article. Sometimes those who write something are simply unaware that there is ambiguity or unclarity in the way they express themselves.
 * --Jhertel (talk) 14:43, 9 February 2020 (UTC)
 * The work you've done listing the terms used will be very helpful in doing all that.
 * -'' SquisherDa (talk) 11:31, 9 February 2020 (UTC)
 * I agree with what you say, and thanks for your kind words.
 * As I hinted, I have almost no knowledge of this area and just came here to inform myself a little bit about it (after first hearing about the concept on QI), but I was left in total confusion. I guess I can't be of much help, as what I'm best at is to make the ambiguous more unambiguous and clear, but I can only do that if I really do grasp what there is an attempt of saying. So my comment just tried to express what I as an unknowledgable reader (on this subject) experienced when reading the article. Sometimes those who write something are simply unaware that there is ambiguity or unclarity in the way they express themselves.
 * --Jhertel (talk) 14:43, 9 February 2020 (UTC)
 * As I hinted, I have almost no knowledge of this area and just came here to inform myself a little bit about it (after first hearing about the concept on QI), but I was left in total confusion. I guess I can't be of much help, as what I'm best at is to make the ambiguous more unambiguous and clear, but I can only do that if I really do grasp what there is an attempt of saying. So my comment just tried to express what I as an unknowledgable reader (on this subject) experienced when reading the article. Sometimes those who write something are simply unaware that there is ambiguity or unclarity in the way they express themselves.
 * --Jhertel (talk) 14:43, 9 February 2020 (UTC)
 * --Jhertel (talk) 14:43, 9 February 2020 (UTC)
 * --Jhertel (talk) 14:43, 9 February 2020 (UTC)

Chimerical colours
I wonder how much accurate quantitative research has been done on the subject. I'll list my own experience, just using the image here. In each case, I looked at the starting image for half a minute. I know, n = 1, plural of anecdote isn't data, yadi-yada. Make of this what you will. I really wonder though, is there enough experimental data for these effects to have this on Wikipedia? And can we really use an image like this? It seems a bit too simplistic to me, because we're all looking at simple uncalibrated consumer displays with all kinds of defects that might cause effects to fail to work or to appear to work even though they didn't. — Preceding unsigned comment added by 77.61.180.106 (talk) 21:56, 14 March 2021 (UTC)
 * The blue spot worked perfectly, until I put a hand in front of my eye, then it disappeared and I saw only black. When I removed my hand, the blue spot reappeared again. The effect was very repeatable and lasted very long. I wonder if the blue dot was only visible because my display cannot generate pure blacks?
 * The red spot was magenta instead of red and appeared slightly darker than the white, but not much. Kind of pastel, really.
 * The orange one worked as advertised; if anything the effect was more pronounced than in the demonstration image.

List of impossible colors
Is there a list of impossible colors that can be seen? I've spent a lot of time looking and some of the only examples of impossible colors I've found are the ones shown as example images in this article. Are there any more?

Wb_to_colours_when_rotating.svg
The section "Colors outside physical color space" includes an image titled "Wb_to_colours_when_rotating.svg". I'm familiar with the concept described in the image caption, of perceiving colors in a rotating disk patterned in black and white. I've demonstrated it myself in the past, and I've read that in the 1950s-60s, this was demonstrated on television and viewers saw colors on black-and-white TVs. But the phenomenon seems unrelated to the rest of the section, and in fact there doesn't seem to be any further discussion (much less explanation) of the phenomenon anywhere in the whole article. ajad (talk) 02:16, 4 February 2024 (UTC)


 * @A. J. A. DeWitt that image describes fechner color, which is illusory colour but not impossible colour, per se. Also not described in body, so I support removal. Curran919 (talk) 07:29, 4 February 2024 (UTC)

Fictional colours Needs to reference Jasper FForde - Shades of Grey and Red Side Story
Jasper Fforde uses colours in these tomes to 'program' abilities (including a resistance to mildew) into the residents of his world, and, in an extreme case uses a particular shade of green (in the green room) to euthanise them. (see Red Side Story published by Hodder in the UK). (8-9)*6*7 * (-1+7-7) &#61; 42 (talk) 00:29, 19 April 2024 (UTC)
 * Mentions like this would need reliable sources showing they're significant cultural aspects of this article's subject; see MOS:POPCULT. - Aoidh (talk) 00:46, 19 April 2024 (UTC)
 * @Argon042 I've read shades of grey and I don't see how its (deeply unphysical) use of color is relevant to this article? Curran919 (talk) 04:56, 20 April 2024 (UTC)