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What of metallic blues, yellows, brown and grayscale color? — Preceding unsigned comment added by 67.203.140.132 ( talk) 02:47, 4 September 2015 (UTC)
i have added some material on the physics of spectral color and integration of the spectral colors in visible light. i have some further ideas on wavelength discussion, alternative light sources for visible light, etc, if a consensus indicates more such material would be desirable. i am open to editing or moving text i created just now to another article. im a newcomer to "color" editing so i am open to suggestion. Anlace 15:32, 20 May 2006 (UTC)
pls add the page non spectral colors. —Preceding unsigned comment added by 82.205.243.3 ( talk • contribs) 20 June, 2007
Both are very inappropriate examples and quite ambiguous terms. " Pink" of course is not spectral, but it may denote not only a low saturation red (i.e. a mixture of red and white), but also those side of purple tones (≈350°) which is close to red (360°=0°). These colors obviously are not mixtures of gray(white) and red. Brown, as stated in article, has HSV: h=30°, s=100%, v=59%, which has maximal saturation, so is nearly a spectral color ( orange), but with low intensity (dark). Incnis Mrsi ( talk) 08:38, 17 April 2010 (UTC)
There are plenty of sources on a cyan spectral color, usually mentioning such wavelengths as 502, 505, 520, sometimes 488 nm (note I don't claim that it is the same as the color of cyan ink). These are not only students' webpages such as [1] [2] [3] [4], but also peer-reviewed publications [5] [6] [7], information about commercially available LEDs and lasers [8] [9] [10] and even a US patent [11]. So, do not do such edits [12] without a discussion. I hope, there are no doubt that the hue of electric blue should be called cyan rather than, say, blue or green.
On the opposite side, please, provide at least one source about "reddish spectral color" which gives an ordinary pink when tinted. Not just verbal declarations "RED + WHITE = PINK", but something demonstrating it numerically or on a plot. Without such a source, I will wipe the pink from this example without a mercy. Incnis Mrsi ( talk) 07:40, 16 September 2010 (UTC)
I think the article should use "can be evoked" instead of "is evoked" in its definition.
The human eye cannot distinguish between monochromatic light of a given frequency and a mixture of frequencies that evokes the same response in its (only 3 types of) colour receptors. In other words: they are the same colour. AlexFekken ( talk) 10:23, 23 April 2012 (UTC)
The article Color triangle illustrates the sRGB color triangle, the gamut of colors that can be made by mixing typical CRT R, G, and B primaries, and shows what ALL spectral colors are outside that range, and by implication of their place on the chromaticity diagram, distinguishable by normal human vision. This idea that it is "almost always possible to tune the R, G and B levels so that the response levels of the colour receptors to the mixture exactly match those produced by the spectral colour" is a common misconception. Not so. Dicklyon ( talk) 15:18, 27 April 2012 (UTC)
Does somebody have a good, scientific source about this? The question refers not only to one of 2012, but also to WP: Articles for deletion/Unique hues. Namely, it should confirm two things:
Of course, if a source also considers some psychological aspects, it would be a bonus. Incnis Mrsi ( talk) 07:55, 18 January 2013 (UTC)
https://en.wikipedia.org/?title=Spectral_color&diff=540523315
A shame on all us that this “clarification” can be visible for more than 12 hours. The color people, why do you promptly go to war when I change red to cyan or so, but sleep when an idiocy is injected to the article? Incnis Mrsi ( talk) 06:47, 11 June 2013 (UTC)
The three cheapest kinds of laser pointers are 650 nm red, 532 nm green, and 405 nm violet. The cheap ones are nominally 5mW, although the green ones tend to be 2-3x overspec, i.e., 10-15mW. Red covers such a huge swath of the spectrum that a 650 nm laser pointer doesn't tell us much. 635 nm laser pointers (more expensive) also look red, just not as much when there's a side-by-side comparison. 670 nm, 808 nm, and 980 nm laser pointers also look red. 532 green, on the other hand, is widely acknowledged as having a very slight yellowish tinge. A more rare and expensive laser pointer in a color known as forest green at 520 nm has a bluish tinge. Another more expensive forest green laser is 515 nm, trends even more towards blue. Green traffic lights in the US are now 505 nm, previously 507 nm (the old 3M lamps). However, traffic lights, even with diodes, are much more broadband. Green traffic lights are intentionally skewed towards blue so that people with the most common sort of color blindness can see them. If you're not paying attention, they look green. However, if you look closely, you are suddenly amazed at how blue they are, almost turqoise. The standard for yellow or amber traffic lights in the US is 594 nm. They also have amber laser pointers (more than $500 for 1mW) at 593 nm. In bother cases, they seem to really look amber.
589 nm laser pointers are marketed as "yellow" but that's kind of tricky. Most people agree that true yellow is further down the scale, although they can't agree on whether it's 580 or 590.
The cheap 405s you get on eBay are actually (and consistently) 403.5. This kind of laser is often advertized as Blu-ray because it's the wavelength used in Blu-ray DVD. However, the color is actually far violet bordering on ultraviolet. Another sort of laser is advertized as "blue" or "445/447/450." These are actually two kinds of lasers so close that their wavelengths overlap. Although they often show up as blue in photos, people who have actually seen them say there's a definite tinge of violet that sometimes shows up in photos. 473 nm laser pointers are marketed as "true blue" although they look more like sky blue. True sky blue or azure may actually be closer to 478. Not that this is necessarily the color of the sky, just the name of a tertiary color, halfway (perceptually) between blue and additive cyan. (Printer or subtractive cyan is a completely different color).
I forgot to mention orange. Here we need to look at bench lasers. 612 nm is a kind of orange, but has a distinctive reddish tinge. 607 nm has a very, very faint reddish tinge. 604 nm looks orange enough that it has neither a perceptible reddish not yellowish tinge.
One last point: people who don't have a lot of experience with lasers can easily be food by the Bezold-Brucke shift, where hues shift with brightness. However, when you've played with or worked with a particular wavelength long enough, you eventually see it in all it's incarnations, at which point you get some idea of where the center of gravity is. Zyxwv99 ( talk) 22:46, 30 March 2014 (UTC)
The article says "One needs at least trichromatic color vision for there to be a distinction between spectral and non-spectral colours..."
That implies that dichromats can't tell the difference between a laser and a gaussian emission centered at the laser. If you have two cones, the ratio of the two cones will change, thus the system has information to discriminate between the two.
Or is it talking about the line of confusion and how the spectral locus becomes confused for other chromaticities along a line?
Incnis Mrsi noted in Special:Diff/560409216 that the current "sample" displays are ad hoc and unprofessional. It doesn't need to be that bad: since the CIEXYZ color space of 1931 and the initial definition of the sRGB in terms of the XYZ, it has always been possible to take a wavelength λ and convert it to sRGB in a very standard way:
The only knob to turn here is the radiance value. I recommend using a uniform radiance value so the differences in luminance is visible. The value should be chosen so that the fewest values run out of the sRGB gamut. For those that do, we will need to do chroma-reduction gamut mapping or something else.
As for the hue angle... I strongly recommended not using HSV/HSL. CAM16-UCS hue is a good fit of Munsell hue, and should be used here.
Someone (probably me) can do it in a Jupyter notebook so people can reuse the results. -- Artoria 2e5 🌉 15:50, 2 March 2021 (UTC)
The table of spectral colors is a bit of a disaster. The 'main' table was put in June 2013 and still reflects most of that uncertainty, having grown organically since then, lacking citations, lacking clarity, lacking cohesion. The vast majority of colors are not even spectral colors.
The lead table was put in November 2021 and I think incorporates all of the information that needs to be in the 'main' table. If we want a "list of colors of high purity", then that can be a thing, but I don't think it belongs in this article. I opt to scrap the 'main' table wholesale and leave the table in the lead. Will wait for some input before I do so. Curran919 ( talk) 08:04, 19 September 2022 (UTC)
![]() | This article is written in American English, which has its own spelling conventions (color, defense, traveled) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus. |
![]() | This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
What of metallic blues, yellows, brown and grayscale color? — Preceding unsigned comment added by 67.203.140.132 ( talk) 02:47, 4 September 2015 (UTC)
i have added some material on the physics of spectral color and integration of the spectral colors in visible light. i have some further ideas on wavelength discussion, alternative light sources for visible light, etc, if a consensus indicates more such material would be desirable. i am open to editing or moving text i created just now to another article. im a newcomer to "color" editing so i am open to suggestion. Anlace 15:32, 20 May 2006 (UTC)
pls add the page non spectral colors. —Preceding unsigned comment added by 82.205.243.3 ( talk • contribs) 20 June, 2007
Both are very inappropriate examples and quite ambiguous terms. " Pink" of course is not spectral, but it may denote not only a low saturation red (i.e. a mixture of red and white), but also those side of purple tones (≈350°) which is close to red (360°=0°). These colors obviously are not mixtures of gray(white) and red. Brown, as stated in article, has HSV: h=30°, s=100%, v=59%, which has maximal saturation, so is nearly a spectral color ( orange), but with low intensity (dark). Incnis Mrsi ( talk) 08:38, 17 April 2010 (UTC)
There are plenty of sources on a cyan spectral color, usually mentioning such wavelengths as 502, 505, 520, sometimes 488 nm (note I don't claim that it is the same as the color of cyan ink). These are not only students' webpages such as [1] [2] [3] [4], but also peer-reviewed publications [5] [6] [7], information about commercially available LEDs and lasers [8] [9] [10] and even a US patent [11]. So, do not do such edits [12] without a discussion. I hope, there are no doubt that the hue of electric blue should be called cyan rather than, say, blue or green.
On the opposite side, please, provide at least one source about "reddish spectral color" which gives an ordinary pink when tinted. Not just verbal declarations "RED + WHITE = PINK", but something demonstrating it numerically or on a plot. Without such a source, I will wipe the pink from this example without a mercy. Incnis Mrsi ( talk) 07:40, 16 September 2010 (UTC)
I think the article should use "can be evoked" instead of "is evoked" in its definition.
The human eye cannot distinguish between monochromatic light of a given frequency and a mixture of frequencies that evokes the same response in its (only 3 types of) colour receptors. In other words: they are the same colour. AlexFekken ( talk) 10:23, 23 April 2012 (UTC)
The article Color triangle illustrates the sRGB color triangle, the gamut of colors that can be made by mixing typical CRT R, G, and B primaries, and shows what ALL spectral colors are outside that range, and by implication of their place on the chromaticity diagram, distinguishable by normal human vision. This idea that it is "almost always possible to tune the R, G and B levels so that the response levels of the colour receptors to the mixture exactly match those produced by the spectral colour" is a common misconception. Not so. Dicklyon ( talk) 15:18, 27 April 2012 (UTC)
Does somebody have a good, scientific source about this? The question refers not only to one of 2012, but also to WP: Articles for deletion/Unique hues. Namely, it should confirm two things:
Of course, if a source also considers some psychological aspects, it would be a bonus. Incnis Mrsi ( talk) 07:55, 18 January 2013 (UTC)
https://en.wikipedia.org/?title=Spectral_color&diff=540523315
A shame on all us that this “clarification” can be visible for more than 12 hours. The color people, why do you promptly go to war when I change red to cyan or so, but sleep when an idiocy is injected to the article? Incnis Mrsi ( talk) 06:47, 11 June 2013 (UTC)
The three cheapest kinds of laser pointers are 650 nm red, 532 nm green, and 405 nm violet. The cheap ones are nominally 5mW, although the green ones tend to be 2-3x overspec, i.e., 10-15mW. Red covers such a huge swath of the spectrum that a 650 nm laser pointer doesn't tell us much. 635 nm laser pointers (more expensive) also look red, just not as much when there's a side-by-side comparison. 670 nm, 808 nm, and 980 nm laser pointers also look red. 532 green, on the other hand, is widely acknowledged as having a very slight yellowish tinge. A more rare and expensive laser pointer in a color known as forest green at 520 nm has a bluish tinge. Another more expensive forest green laser is 515 nm, trends even more towards blue. Green traffic lights in the US are now 505 nm, previously 507 nm (the old 3M lamps). However, traffic lights, even with diodes, are much more broadband. Green traffic lights are intentionally skewed towards blue so that people with the most common sort of color blindness can see them. If you're not paying attention, they look green. However, if you look closely, you are suddenly amazed at how blue they are, almost turqoise. The standard for yellow or amber traffic lights in the US is 594 nm. They also have amber laser pointers (more than $500 for 1mW) at 593 nm. In bother cases, they seem to really look amber.
589 nm laser pointers are marketed as "yellow" but that's kind of tricky. Most people agree that true yellow is further down the scale, although they can't agree on whether it's 580 or 590.
The cheap 405s you get on eBay are actually (and consistently) 403.5. This kind of laser is often advertized as Blu-ray because it's the wavelength used in Blu-ray DVD. However, the color is actually far violet bordering on ultraviolet. Another sort of laser is advertized as "blue" or "445/447/450." These are actually two kinds of lasers so close that their wavelengths overlap. Although they often show up as blue in photos, people who have actually seen them say there's a definite tinge of violet that sometimes shows up in photos. 473 nm laser pointers are marketed as "true blue" although they look more like sky blue. True sky blue or azure may actually be closer to 478. Not that this is necessarily the color of the sky, just the name of a tertiary color, halfway (perceptually) between blue and additive cyan. (Printer or subtractive cyan is a completely different color).
I forgot to mention orange. Here we need to look at bench lasers. 612 nm is a kind of orange, but has a distinctive reddish tinge. 607 nm has a very, very faint reddish tinge. 604 nm looks orange enough that it has neither a perceptible reddish not yellowish tinge.
One last point: people who don't have a lot of experience with lasers can easily be food by the Bezold-Brucke shift, where hues shift with brightness. However, when you've played with or worked with a particular wavelength long enough, you eventually see it in all it's incarnations, at which point you get some idea of where the center of gravity is. Zyxwv99 ( talk) 22:46, 30 March 2014 (UTC)
The article says "One needs at least trichromatic color vision for there to be a distinction between spectral and non-spectral colours..."
That implies that dichromats can't tell the difference between a laser and a gaussian emission centered at the laser. If you have two cones, the ratio of the two cones will change, thus the system has information to discriminate between the two.
Or is it talking about the line of confusion and how the spectral locus becomes confused for other chromaticities along a line?
Incnis Mrsi noted in Special:Diff/560409216 that the current "sample" displays are ad hoc and unprofessional. It doesn't need to be that bad: since the CIEXYZ color space of 1931 and the initial definition of the sRGB in terms of the XYZ, it has always been possible to take a wavelength λ and convert it to sRGB in a very standard way:
The only knob to turn here is the radiance value. I recommend using a uniform radiance value so the differences in luminance is visible. The value should be chosen so that the fewest values run out of the sRGB gamut. For those that do, we will need to do chroma-reduction gamut mapping or something else.
As for the hue angle... I strongly recommended not using HSV/HSL. CAM16-UCS hue is a good fit of Munsell hue, and should be used here.
Someone (probably me) can do it in a Jupyter notebook so people can reuse the results. -- Artoria 2e5 🌉 15:50, 2 March 2021 (UTC)
The table of spectral colors is a bit of a disaster. The 'main' table was put in June 2013 and still reflects most of that uncertainty, having grown organically since then, lacking citations, lacking clarity, lacking cohesion. The vast majority of colors are not even spectral colors.
The lead table was put in November 2021 and I think incorporates all of the information that needs to be in the 'main' table. If we want a "list of colors of high purity", then that can be a thing, but I don't think it belongs in this article. I opt to scrap the 'main' table wholesale and leave the table in the lead. Will wait for some input before I do so. Curran919 ( talk) 08:04, 19 September 2022 (UTC)