Yes, Virginia, there is a magenta

[n2doc]

By Chris Foresman | Last updated February 18, 2009 5:20 AM



There is a nasty rumor making its way around the interconnected series of tubes we call the Internet. The rumor was sparked by an article on The Neurostimulation Technology Portal by Liz Elliott entitled "Magenta Ain't A Colour," which has since had people exclaiming, "Fact: Magenta isn't a color," or, "Magenta is a lie." The truth is a little more complicated than that, but I assure you that magenta is not a lie—or at least not any more a lie than any other color.

See, what we call the "visible spectrum" is really a very narrow band in a much larger spectrum of electromagnetic radiation. It is visible because our eyes have cells called "cones" in the retina that are sensitive to these wavelengths—in the range of about 400–700nm—to varying degrees. Some of the cones are sensitive to longer wavelengths, some to medium wavelengths, and others to shorter wavelengths. These wavelengths correspond to (roughly) what we call red, green, and blue light, and form the basis of the RGB color model used by digital images, TVs, flat panels, and more.


As visible light enters the eye and strikes the cone cells, the cells send electrical signals along the optic nerve to the brain. This is how our body "senses" light. Our brain interprets those three separate sensations to produce the perception that we call "color."

So back to this rumor that magenta somehow isn't a color. Elliott's thesis centers on the argument that magenta appears nowhere on the spectrum of visible light, so it therefore isn't a "real" color. If you look at a standard CIE chromaticity diagram, which maps wavelengths of light according to human perception, you'll note that every point along the curve corresponds to a single wavelength of light. Magenta, as it were, lies along what's commonly called the "pink-purple line" that runs across the bottom. All colors along this line do not exist as single wavelengths. But, all points inside the "color bag" above that line do not exist as single wavelengths, either.


more:

http://arstechnica.com/science/news/2009/02/yes-virgina-there-is-a-magenta.ars

[AndyA]

1. I read about a young man in Canada who created a magenta-colored

decal for use on windows. It seems birds can see the color, and humans cannot, so the window looks clear to humans, but birds can tell there's something there and don't fly into the glass.

[n2doc]

4. I think it was a decal that absorbed UV light n/t

[Heidi]

2. As a painter, I have to agree: Yes, there is a magenta,

and it's not just a soft pastel stick, an oil color or an acrylic. It's a color I've observed in nature.

[DCKit]

3. You've saved the lives (and careers) of countless decorators and designers today. n/t

[hunter]

5. Humans don't see colors well compared to birds.

Our mammalian ancestors managed to misplace a good portion of their color vision somewhere, and the replacement we primates got is cobbled together from whatever bits were left. We are nominally trichromats, but it's complicated by processing issues.

Oh well, I suppose it makes it easier for us to build color televisions. ("God's Will" according to some demented souls...)

Even so there are colors we can see that can't be reproduced on color monitors, and other colors that don't properly register within our brains.

Birds are tetrachromic. The rainbow they see is a lot richer and can't be flattened into any sort of "color bag."

[xchrom]

6. i see magenta. nt

[Bill McBlueState]

7. All depends on how you define "color"

If by "color" you mean a particular wavelength of light, then no, magenta isn't a color. But most people don't define "color" that way.