RYB and CMY theory?

[Omar]

All the color theory that I've come across is based on the RYB color wheel:

 

http://upload.wikimedia.org/wikipedia/c ... el.svg.png

 

That's the subtractive wheel. Meaning, when mix two colors, they'll become darker. That's the reason for the lack of cyan and magenta. Truth is, in a real subtractive wheel, the primary colors should be CMY, the ones used for printing. That can achieve any color and has the same amount of colors as the additive RGB wheel. However, mixing all three will result in black, while mixing RGB will give white.

 

So why are we basing color schemes on a broken wheel? Can anyone fill me in here? Am I missing something or am I just right?

[pryomancer]

I studied your post for like 10 minutes and I still don't fully understand it. But the RGB is based on light, whilst CMYK is based on colour.

 

If you take a red, green and blue light and shine them together it makes white.

 

Take the same colours you'll get a sloppy brown thing (black is used because sloppy brown has limited uses).

 

 

 

Remember RGB is designed for screens, CMYK for printing. That's where the difference lies. A monitor uses a combo of red green and blue lights to make up the image. A piece of paper doesn't use light, the colours are physically there.

[Nadril]

Remember RGB is designed for screens, CMYK for printing. That's where the difference lies. A monitor uses a combo of red green and blue lights to make up the image. A piece of paper doesn't use light, the colours are physically there.

 

 

 

This. RGB is light, CMYK isn't.

[Omar]

That's not what I mean. I know how the colors blend subtractively and additively. But in most books, you'll be told the primary colors are RYB. They're not. With RYB, you won't be able to produce a real cyan or a real magenta. Also, because the colors are placed wrong, color scheme theory like this: http://www.tigercolor.com/color-lab/col ... monies.htm

 

is wrong. For example, that link says red and green are complementary; they're not. If the primary colors were instead CMY, the wheel and the schemes would be right. For example, the complementary of green would be magenta. So why do all these art theory books use RYB instead of CMY?

[pryomancer]

'Real magenta' and 'real cyan' are produced by a computer screen. You would never find those true colours in nature.

 

 

 

The naturally produced cyan is much more subdued. Computer cyan is the mix of the light-produced RGB, so it can become very vivid.

 

 

 

RGB was invented for computer screens anyway, the colours will never properly match real life. Even when printing you have to be careful, a colour on screen may come out much differently on paper.

[Omar]

You can still see magenta even in subtractive color, as in off-screen. It's possible to obtain cyan and magenta, despite what RYB blends show.

 

 

That's way closer to magenta than the RYB color wheel (see first post) can go, isn't it?

[dsavi]

RGB was invented for computer screens anyway, the colours will never properly match real life.

 

One little correction there- RGB was not "invented", it's just the way that mixture of wavelengths works.

 

 

 

Since I have no idea what the OP is asking anyway, I'll ask this: Why are you leaving HSL/HSV out in the dark, lonely and unloved?

 

 

 

Don't be offended HSL, they don't mean it personally. :(

[Omar]

Simply said, I'm wondering why we use the RYB color wheel - which is wrong - for color harmonies like triads, split-complementaries etc. like this site and most color theory books do?

[Nadril]

Oh, that.

 

 

 

It's less about RGB/CMYK and more about just color in general. Color theory doesn't need to fall under a certain color system, especially when in printing often times spot color will get used, which is a specific pantone color, not a mix of RGB or CMYK.

 

 

 

 

 

from the site though:

 

 

 

The color wheel is designed so that virtually any colors you pick from it will look good together. Over the years, many variations of the basic design have been made, but the most common version is a wheel of 12 colors based on the RYB (or artistic) color model.

 

 

 

It's just a placement of colors that in various combinations look good together. I'm not sure the big reason behind RYB but it clearly works. You just need to think of everything as just color, and not as mixtures of RGB and CMYK (which can not effectively produce every color in the color spectrum))

 

 

 

 

 

 

Picture of a "color spectrum". As you can see even a monitor display can not effectivly display everything, nor can CMYK or Hexecrome (which is CMYK + Orange and Green)

[Omar]

The color harmonies work in geometric forms though.

 

For example, a triad is an equilateral triangle, a square scheme is, well, just that, a square. I assume that the geometry creates a certain sense of balance and contrast.

 

But in RYB where the color placements are wrong, the harmonies no longer make scientific sense, and are almost always off geometrically. For example, red and green as complementary colors aren't as contrasted as red and magenta, and won't neutralize each other in the same way G and M will (one gets brown while the other gets black or white, depending on whether you're using subtractive or additive).

 

Now, if it works, how or why? Our eyes see in RGB/CMY, so I'm guessing the best balance and contrast is obtained from RGB/CMY.

[Nadril]

Our eyes see in RGB/CMY

 

 

 

They don't though. If you read everything I had posted I stated that both RGB and CMY(K) combinations can only create a minor part of the full, visible, color spectrum. Our eyes simply see color, that's it.

 

 

 

 

 

The RYB primary colors became the foundation of 18th century theories of color vision, as the fundamental sensory qualities that are blended in the perception of all physical colors and equally in the physical mixture of pigments or dyes. These theories were enhanced by 18th-century investigations of a variety of purely psychological color effects, in particular the contrast between "complementary" or opposing hues that are produced by color afterimages and in the contrasting shadows in colored light. These ideas and many personal color observations were summarized in two founding documents in color theory: the Theory of Colors (1810) by the German poet and government minister Johann Wolfgang von Goethe, and The Law of Simultaneous Color Contrast (1839) by the French industrial chemist Michel-Eugène Chevreul.

 

 

 

Subsequently, German and English scientists established in the late 19th century that color perception is best described in terms of a different set of primary colors -- red, green and blue (RGB) -- modeled through the additive, rather than subtractive, mixture of three monochromatic lights.

 

 

 

Painters have long used more than three RYB primary colors in their palettesand at one point considered red, yellow, blue, and green to be the four primaries[1]. Red, yellow, blue, and green are still widely considered the four psychological primary colors[2], though red, yellow, and blue are sometimes listed as the three psychological primaries [3], with black and white occasionally added as a fourth and fifth [4].

 

 

 

The cyan, magenta, and yellow primary colors associated with CMYK printing are sometimes known as "process blue", "process red", and "process yellow".

 

 

 

Source:[1]

 

 

 

Maybe that'll clear it up? There actually is a model based around RGB as well.

 

 

 

 

 

For example, red and green as complementary colors aren't as contrasted as red and magenta

 

 

 

They're supposed to be stark opposites, and red and green are. The RYB color wheel people use is in no way broken.

[Omar]

Red and green aren't stark opposites, or at least not in the way our eyes see. Stare at something red for a long time, then take your eyes away from it; you'll see cyan everywhere. Star at something green for a long time and you'll see magenta everywhere.

 

 

 

The RYB wheel is broken. Unless you add two other colors as primaries - black and white - you'll lack these two colors.

 

 

That's wrong. As far as I've observed while painting, you can't possibly achieve black with only those three. You can with CMY (lack of color for white, all colors for black [the key channel is used because of transparency of ink when printing]) or RGB (lack of color for black, all colors for white).

[Nadril]

Meh I don't really know what else to tell you. Everything I've been taught about color theory is based on RYB, and I am much more inclined to believe my professors and color theorists than you.

 

 

 

I don't really have any other explanation for you.

[WolfieMario]

Our eyes see in RGB/CMY

 

Well, scientifically, our eyes see red, green, blue, and brightness. The red, green, and blue are perceived by "cone" cells, while the brightness (which is both black and white) is perceived by "rod" cells. There are no cells which specifically detect CMY, and the cone cells for RGB detection aren't present in equal amounts. Interestingly enough, it seems that the amounts of a particular type of cone vary a lot between individuals, but usually more red cones (aka Long cones) are present than green cones (Medium cones), and the blue cones (Small cones) are almost always the least common:

 

Photobleaching can be used to determine cone arrangement. This is done by exposing dark-adapted retina to a certain wavelength of light that paralyzes the particular type of cone sensitive to that wavelength for up to thirty minutes from being able to dark-adapt making it appear white in contrast to the grey dark-adapted cones when a picture of the retina is taken. The results illustrate that S cones are randomly placed and appear much less frequently than the M and L cones. The ratio of M and L cones varies greatly among different people with regular vision (e.g. values of 75.8% L with 20.0% M versus 50.6% L with 44.2% M in two male subjects).[6]

 

[source]

 

 

 

I can see what you mean about the RYB color wheel not allowing for the production of every possible color, but the RGB and CMY(K) systems do not allow for this either. People try to develop systems like these to quantize their descriptions of color, but doing so also limits the available possibilities. Of course it's easy to tell someone "#00FF00" or "#FF00FF00" or "one part blue, two parts yellow". But none of these color models will ever allow someone to truly have every color possible. It's really more of a matter of personal preference, no system is particularly right or wrong. Personally, I choose to work with RGB, despite the fact that it has the least amount of possible colors, because I prefer designing computer graphics and screenshot fakes. Someone who prefers working on the computer to create things that will be printed out, such as posters, would use CMY(K). And someone who likes to paint would likely be more inclined towards RYB. In the end, it boils down to how people prefer to do things

[Nadril]

Print isn't just CMYK. It's also spot color a lot of times and rarely it is Hexecrome (which can produce more colors from the visible spectrum than CMYK).

 

 

 

 

 

Personally, I choose to work with RGB, despite the fact that it has the least amount of possible colors, because I prefer designing computer graphics and screenshot fakes.

 

 

 

You really don't have an option to work with anything else if you're digital. Even in the print industry images aren't converted into CMYK until after post-process effects have been finished, but before layout.

[Omar]

I don't really care about the amount of colors obtained since I work in digital so I'll never really have the choice to work with any other amounts of colors that can be reached - I'm not sure why I brought that up in the first place - I'm just wondering which gives the best color schemes when you use schemes like the ones in my second post. No matter which wheel you use, a triad will always be an equilateral triangle, and a complementary will always be a straight line. But depending on the wheel, the colors won't be the same.