Red, Yellow, and Blue
daveeddy.com
daveeddy.com
While the explanation of additive and reductive color combining was interesting, I think it's important to note that it's because you're dealing with waves of light being absorbed or reflected.
I learned more about color theory and light in stage lighting classes than anywhere else. Teaching your brain how to combine colors correctly to get the exact shades you're looking for on the stage is hard. You really do have to forget a lot of what you learned in art classes to be effective. Understanding how colored light is absorbed, reflected, or otherwise changed on makeup, furniture, fabrics, and other surfaces added a whole different level of complexity not found in typical art classes.
Searching Google for "stage lighting color wheel" reveals more wheels similar to the one that you see at the author's really cool implementation[0].
It's our eyes. Our eyes are (roughly) RGB, therefore a RGB monitor is a best spectrum match for our eyes, therefore it's how computers and printers deal with it (CMY/K/ is just the inverse of RGB).
For many animals, even our best high end lifelike wide-spectrum display cuts out or inaccurately represents portions of the spectrum they can see.
It's not that easy though
http://en.wikipedia.org/wiki/Color_vision
> The cones are conventionally labeled according to the ordering of the wavelengths of the peaks of their spectral sensitivities: short (S), medium (M), and long (L) cone types. These three types do not correspond well to particular colors as we know them. Rather, the perception of color is achieved by a complex process that starts with the differential output of these cells in the retina and it will be finalized in the visual cortex and associative areas of the brain.
> For example, while the L cones have been referred to simply as red receptors, microspectrophotometry has shown that their peak sensitivity is in the greenish-yellow region of the spectrum. Similarly, the S- and M-cones do not directly correspond to blue and green, although they are often depicted as such. It is important to note that the RGB color model is merely a convenient means for representing color, and is not directly based on the types of cones in the human eye.
Also there are alternative color spaces like YUV: http://en.wikipedia.org/wiki/YUV
The choices of RGB in trichromatic reproduction systems are such that the individual contribution of each minimizes the cross-cone activation in the eye, allowing greater fidelity (widest gamut) in color reproduction with only three sensors at input and three emissive colors at output. In other words, if you're going to use analog electronics and passive filters, it helps to make the selected primary frequencies as functionally orthogonal and isolated as possible.
Consider the quality of an absorptive filter and/or response profile of a pixel on CMOS sensor; so long as a it has a strong peak at the primary frequency, then we're not too concerned about leakage from other frequencies into it; nor are we too concerned that nearby colors could leak a little into the other two channels because this will mostly be correlated with overall luminance, which makes it very hard for the eye to discern upon reproduction (it looks a little more washed out).
This is why Young and Helmholtz initially identified red, green and blue as primary colors way back in the early 19th century. They tried to identify three specific color frequencies that could be used to mimic other pure frequencies through re-combination in test subjects, based on a theory about how the eyes worked. While these colors do not correspond to sensory peaks for each cone cell type, it turns out the retina/visual cortex's post processing (the "opponent-process" discovered by Ewald Hering) derives hue from the combined activation ratios, and is thus bypassed by using combinations of RGB to create hues as opposed to direct spectral activation.
For one, I learnt in school that the primary colours where red, green and blue, and later that the substractive primary colours where cyan, magenta and yellow. So nothing different from the RGB/CMYK colour wheels everyone uses.
Second, well nobody will ever be able to create all colours from mixing red, yellow and blue, plain and simple. Unless your red is actually magenta and your blue is actually cyan.
At this point, you have just created a colour picker that uses cyan, magenta and yellow with no easy way to change lightness (without the K scale, you will have to manually change every colour level to match the global lightness you want).
But his implementation has a brightness slider and uses "real" red instead of magenta, and "real" blue instead of cyan, which makes it a BMYK color wheel, and which prevents it from reproducing all colours. Even just setting brightness to the minimum gives a dark brown instead of black, because he's mixing colors from different models.
I thought I was going insane for a moment, because (though it's been years) I swore I was taught the same thing. Perhaps it's an artifact of having grown up in a "modern" world where additive and subtractive palettes are important, but thinking back on it, I remember the science classes and the "light experiment" of using different colored flashlights to produce white (from red, green, and blue--though not perfect because of the colors of cellophane used, and kids generally don't care).
While I realize art has a long history (and I appreciate the contributions it has made to society at large), scientific discovery has arguably made more important inroads on the why and how of colors. Interestingly, the Wikipedia article [1] on the subject links to the "four psychological primary colors" [2] of red, green, yellow, and blue. Yes, the RYB model is interesting (at least historically) and important to painters, but even prior to modern science what constituted "primary colors" seems to have been more inclusive than just a three color system.
I don't wish to seem ungrateful: I do appreciate the work the author put into the article (and appreciate the dissemination of the paper linked to on the RYB system), and I admit (not being an artist) that it's difficult for me to understand what seems like fairly superficial complaints relayed through him from his artist friend. It almost seems like it's being dismissive of what we know about our visual physiology for no other reason than "this is how they used to do it."
Interesting nevertheless, but like you, it's difficult for me to see the point: So there's a niche need for artists who don't like the existing color system? Okay, great. Give them what they want and move on.
For me the RYB model just seems more intuitive. It just feels natural that green would be a bluish-yellow. It still seems odd that red and green can be combined at all, much less produce a pure yellow.
But that's just what the CMY(K) model says. The CMY(K) model is the meaningful one in everyday life. In actual reality, with human eyes observing physical light filtered by pigments, blue is just cyan with a little magenta in it, and red is just magenta with a little yellow in it. The truth is, in the real world, you will never be able to make cyan or magenta if all you have is yellow, red and blue paint. But you will be able to make red or blue if you have yellow, magenta and cyan paint.
I think this might just be a case of people insisting to use less precise but more familiar names for colours, maybe. Maybe in English "cyan" and "magenta" sound like strange colours while blue and red sound more familiar and comforting. But insisting on using blue instead of cyan actually restricts your ability to draw colours.
When people first start learning digital painting (painting in Photoshop, Gimp, etc), a lot of them draw landscapes with chartreuse grass, because they used the greenest green on the color picker. Artists in other mediums don't usually have this problem, because rarely-useful colors like #00FF00 aren't included in the typical pigment set.
It really depends on your priorities for the use case. Sometimes you want to give as many options as possible, sometimes it's more important to make it really easy to get something that looks ok and hard to accidentally get something overly neon.
So not being able to get the luridly luminous magenta and cyan you can get on a screen is a feature, not a bug.
http://newsfeed.time.com/2012/03/07/does-the-color-pink-exis...
http://gizmodo.com/if-the-color-pink-doesnt-scientifically-e...
http://blogs.scientificamerican.com/observations/2012/03/05/...
If there's one saving grace, I suppose it's that we're not tetrachromatics, right? ;)
http://discovermagazine.com/2012/jul-aug/06-humans-with-supe...
Importantly, I was thinking along the lines of some insects and spiders that are capable of seeing into the UV spectrum for sexual signalling or locating food sources (e.g. flowers). Which reminds me that there's been some evidence that suggests those who've had cataract surgery may be able to see deeper into the violet spectrum without a UV-filtering obstacle in place. But that's likely just the function of the blue-sensitive cells.
Colors arise from the presence (and absence) of 1...N simultaneous wavelengths triggering a suite of inexact biosensors.
If you ever see magenta in a natural rainbow, it's only because there are two-or-more spectrums are overlapping in a messy and inexact manner.
TLDR: "Color" is to "wavelength" as "taste" is to "chemical".
Apparently the common color wheels, Red Yellow and Blue, are based on Newton’s prism experiments [1].
[1] http://learn.leighcotnoir.com/artspeak/elements-color/primar...
Yes, because physiologically, that's how we're wired. We have receptors for red, green, and blue wavelength light. Everything else is just a matter of how they get excited.
Apple tried this, kind of.
If you're interested in a color wheel for a picker design that has perceptual evenness, check the Munsell CS (http://en.wikipedia.org/wiki/Munsell_color_system) ... in a color picker it might be cool to select via projections of CIELAB as the refined version of same.
The second explanation (or suggestion, at least) is more psychological. In the distant past our eyes had only two colour receptors, and our brains measured the relative difference between the two, so we percieved colour on a one-dimensional line - e.g. more "warm" long wavelengths or more "cool" short wavelengths. At some point we evolved a third receptor, and our brains began processing this extra input as another perceptual axis orthogonal to the existing one, which could be described as purple/green against the original red/blue. Exploring this new 2D space results in a continuous rainbow around the edges.
I also recommend watching this short video on the origin of ROYGBIV, and why Indigo probably doesn't really deserve it's own letter - but it got one, because of European music notation: http://www.theatlantic.com/video/archive/2014/01/why-roygbiv...
RGB is just 3 pixels of different intensities, next to each other and sitting on your desk.
Magenta? sure, everyone agrees is a bastard color- but cyan is on the rainbow in the spot labeled 'blue', and _your_ blue is labeled 'indigo'.
CAN'T PROVE ME WRONG IMMA COLOR EXPERT