RYB primaries

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There are two phrases I keep seeing written down all over the internet that cause my blood pressure to increase.

The first is that the colour primaries are red, yellow and blue (RYB). And the second is that the primaries are colours that cannot be made by mixing other colours. Neither of these statements are true, of course.

The first statement makes no distinction between additive colour mixing (of lights) and subtractive colour mixing (of paints and inks) but subtractive colour mixing is normally implied. However, RYB is a relatively poor choice for three colour primaries. The range of colours that can be produced is actually quite small. For most painters and artists it doesn’t matter because very few work in just three primaries – if they did so they would probably be frustrated by the small gamut of colours achievable. Many artists (painters) will use 10 or more basic colours to mix their palette. However, there is a group of people who care passionately about the gamut of colours that can be obtained by mixing three colour primaries – that is the people who work for companies such as HP and Canon. These companies make CMYK printers for the consumer market and their jobs depend upon consumers liking their printers. They understand that the largest gamut (in subtractive mixing) can be obtained if the primaries are cyan, magenta and yellow (CMY). The teaching of RYB as the (subtractive) primaries should be stopped. It’s already gone on for far too long.

One reason I don’t like the teaching of RYB as being the subtractive primaries, in addition to the fact that it is wrong, is that it confuses people who are trying to learn colour theory. This is because red, yellow and blue seem to be quite pure colours and this encourages people to hold the second belief I don’t like which is that the primaries are pure colours that cannot be mixed from other colours. If people understood that the primaries were CMY it would be less tempting to hold this belief about the purity of the primaries. Of course, if you make a palette of colours of three primaries then it is true that no mixture of two or more colours from that palette can match any of the primaries. However, there are other colours (that are outside the gamut of the primary system) that could be mixed together to match the primaries. This false notion of purity confuses the real issue – that is, that the subtractive primaries are cyan, magenta and yellow because the additive primaries are red, green and blue. Look at this picture below:

The additive primaries are red, green and blue and the secondaries are cyan, magenta and yellow. Correspondingly, the subtractive primaries are cyan, magenta and yellow and the subtractive secondaries are red, green and blue. Simple.

I wrote about this before so for a slightly different perspective see my earlier post.

Perhaps I am so agitated about it today because I am just watching England getting trounced by Ireland at rugby when the Grand Slam was so tantalisingly close. Or maybe I will feel just the same tomorrow.

13 thoughts on “RYB primaries

    David Briggs said:
    March 20, 2011 at 2:07 pm

    You can say that again!

    Perhaps the most shocking thing is that even today most art students have never heard of opponency – the single most fundamental thing we know about hue perception – because it doesn’t fit with the conventional “colour wheel”.

    I see the three historical primaries as a confusion of the three subtractive primaries (yellow, blue-red, and green-blue) and the four psychological primaries (yellow, red, blue, and green), and so as ancestral to both systems. Their survival seems to be due to the broader “two culture” syndrome that you wrote about a while back. There’s a deeply self-satisfied tradition in art teaching that is suspicious of anything it labels as “science”, or at least science that is too new. It’s like there’s a line between Chevreul and Helmholtz, and everything on the wrong side of that line is obviously not relevant to art.

    The “Dinotopia” illustrator James Gurney recently published a book called “Color and Light”, which is a very good general introduction to a more analytical approach to painting. It was/is an Amazon #1 bestseller in the art category, and I’m hopeful it will speed the extinction of a few more dinosaurs, if you follow me!

      swestland responded:
      March 26, 2011 at 9:57 am

      Hi David,
      Thanks for this. Glad it is not just me! 🙂

      I agree about your comment about confusion between the subtractive primaries and the psychological primaries. Because of this unfortunate notion that primaries are pure people think the primaries must come from the set red, yellow, green, blue (the psychological primaries).

      You’re also right about the suspicion of science. Though it goes both ways of course. There is ‘fault’ on both sides. A great example of an artist who embraces science is Bruce McEvoy – http://www.handprint.com/

      Thanks for the tip on Dinotopia. I have not read that. I’ll order it today!!

    Lori Sawaya said:
    March 28, 2011 at 5:06 pm

    I work in the realm of paint and architectural design. If RYB annoys you, then the “Color Consultant Certification” courses currently being offered across the landscape of all things paint and color would REALLY annoy you. Rugby game notwithstanding.

    Herds of “color experts” are being “certified” on an almost daily basis.

    The wealth of misinformation about color just keeps getting perpetuated.

    Blogs like yours are indeed unique. Love the attitude. Love the bona fide color expertise.

    You rock.

      swestland responded:
      March 28, 2011 at 5:23 pm

      Hi Lori

      Thanks for your very kind words. I really appreciate them. I would just say though that I am probably not right about everything. That’s why I tagged this post under knowledge *and* opinions/rants. Haha!!

      However, I certainly agree that there is such a load of rubbish written and spoken about colour. It’s unbelievable. And you’re right – the misinformation just keeps getting perpetuated. How do we stop it??


    funcolors said:
    March 28, 2011 at 5:43 pm

    Don’t think we can stop it.

    We can only work tirelessly to counter it. Being outspoken and speaking to color with a big confident voice – like yours – is the best remedy.

    I take the same stance as you – I’m probably not right about everything either. But I’m pretty sure my opinions are more on target than off.

    Which is why opinions/rants are important to keep putting out there. There is a huge color tribe connected via social media who are like-minded. Meaning they are sick and tired of the repetitive color tips & tricks and imaginary color “facts” in general that’s being hawked as color education.

    A few years ago I started calling this movement of color professionals railing against the staid memes and folklore of color The New Age of Color.

    You definitely need to get connected to the tribe. You can find many of us on LinkedIN – http://tinyurl.com/2g7mw4e. And also Color Friends on FaceBook – http://tinyurl.com/5set5gr

    I welcome every fellow dissenting voice I can find. lol!

    David Briggs said:
    November 4, 2012 at 2:36 pm

    Hi Steve,

    Hope might like to know that I’ve been revising my website this year. The sections up so far are 1 (introduction), 4 (additive mixing), 5 (subtractive mixing) and 6 (colour mixing in paints). The last includes an elaboration of my discussion of the history of concepts of primary colours:

    DrShelp said:
    February 19, 2013 at 5:07 am

    Don’t let me get in the way of the straw man thrashing but…
    RYB, RGB, CMYK are all simply imperfect models trying to find a way to describe and utilise colour. All have a gamut that fails to match the gamut perceivable by the human eye and all have other limitations.

    Whilst RGB / CMYK have the neat ability to mirror each, other which no doubt appeals to those who like concrete concepts, they are both still limited models.

    No doubt artists who work with paint probably feel there is little benefit to them in the additive RGB model because they are not working with lcd screens and probably see little logic in learning a reverse model and converting to their medium.

    CMYK may not appeal to an artist painter as much as is does to those working in the printing industry because the painter rarely restricts themselves to the 4 CMYK model primaries when buying their oil paints.

    In fact outside of the printing industry very few occupations actually work with the CMYK primaries most are working with secondary colours and primaries may therefore seem less tangible and accessible to them.

    Yes RYB has a more limited gamut and it is an imperfect model but we are simply talking about varying levels of imperfection attempting to describe an ‘experience’ that even goes beyond the complex CIELAB models that most would have a brain fart attempting to conceptualise.

    For those who cross between physical mediums (subtractive) and the PC screen (additive) working with colour during their occupation, then the RGB / CMYK models are the obvious choices. Even though they are imperfect and limited.

    In my view RYB does still have its place as the historical and arguably the most simplistic intuitive model for those working with colour in physical (subtractive) mediums that do not require reverse mapping or larger gamut.

    Don’t believe that RYB is more intuitive?
    Ask 100 people what colour result you will get from mixing blue and yellow together, I would suggest that there is at least the possibility of getting 100% correct answer.

    Ask the same 100 people what colour result you will get from mixing cyan and yellow together and I would bet that you get a sizable number of people asking what colour cyan is.

    Perhaps some of that difference is due to education, after all cyan is just a word but some of it is probably also due the the natural connection with sensitivity peaks of Photopic Response at around 555nm and an innate comprehension that yellow and blue are related to green.

    Also moving away from colour models and the math lets not forget that colour is experiential and conceptual, after sensory input has occurred there is also neural interpretation of the input within the visual cortex and even within those who have ‘average’ colour vision there is a range of interpretation of the perception of colour.

    It is good to remember that our biological colorimeters are not pieces of laboratory equipment with measurable constants, therefore does it really matter what model we chose to help us grasp a concept that even the colour scientists struggle with?

      David Briggs said:
      February 20, 2013 at 12:11 am

      The notion that a set of colourant primaries “should” mix all colours and is therefore “imperfect” if it doesn’t is a hangover of what I have called the “imtermixture theory” of colour mixing, the historical idea that all colours are “made of” three primaries (see the link in my last reply).

      Fundamentally the problem with the RYB primaries is not that they are “more imperfect” that CMY, it is that they perpetuate a confusion of two very important concepts, the psychological primaries of colour perception (Y, G, B, R) and the optimal subtractive primaries of colorant mixing (Y, GB, BR).

        DrShelp said:
        February 20, 2013 at 1:03 am

        Hi there well actually both RYB and CMYK models claim exactly the same thing they both claim to ‘create’ all other colours within their limited gamut. Which is perfectly true.

        However ‘mixing’ is a different thing altogether, most experienced artist painters will attest to the fact that both RYB and CMYK fail to ‘mix’ all other colours. That is partly because of the gamut limitations for both models, partly because CMYK works better for ‘layering’ rather than ‘mixing’, partly because physical colour mixing has some inherent challenges due to dominance of some physical pigments due to their molecular structure individually and in combination, and partly due to the spectral energy distribution of the physical pigments not necessarily matching with the perceived colour.

        IMHO the argument that one imperfect model should only ever be used in comparison to another imperfect model is flawed.

        CMYK is simply another model with its own applications and those in the printing industry have found some use for it, however a point of particular note in relation to the CMYK model is that many paint manufacturers have found that ‘O’ orange and ‘G’ green needs to be added to the CMYK model i.e. CMOYGK due to the hue defecits when trying to print swatches for their paint ranges.

        I find that CMYK / RBG has great appeal to those wishing to find a concrete solution to the colour problem, unfortunately it is just another simplistic and limited model.

        CMYK also lacks the intuitive benefits that RYB has for many people, I suspect that is most likely due to cone wavelength sensitivity distribution and population perceptual differences.

        When trying to think in concrete terms (CMYK is the way) you need to bear in mind your perspective is based upon your own experience of colour which is likely to be different to the experience that others have.
        Artistic painters understand that concept but are often unable to express and vocalise it to the satisfaction of those in the printing/pc occupations who might desire a more tangible solution.

        The RYB model does have its uses and I suspect it will continue to be taught and used in the artistic disciplines for a very long time, that is until we humans evolve and see colour differently.


    David Briggs said:
    February 20, 2013 at 10:35 am

    DrShelp, I’ll refrain from plowing on here until Steve W has had a chance to get a word in! But meanwhile please read the page I linked to when you get a moment, as it should make the two points raised in my last reply a little clearer.

    DrShelp said:
    February 20, 2013 at 11:37 am

    Yes I have seen your contribution it does not change my comments at all, as with all fields there will be ongoing development of understanding. The mere fact that a previous notion in relation to a model (primaries cannot be mixed) is shown to be unfounded does not necessarily mean that the model holds no useful purposed as is being suggested here.

    My contention is that is incorrect, the RYB model still holds value for simple intuitive comprehension of colour mixing particularly for the artistic fields and for many it is a more useful model than CMYK.

    I would suggest this is nothing more than the inability to comprehend that not all human brains function in a particular way. I accept that you worship at the alter of CMYK, I personally feel it is a model that is of limited value outside of the area of desktop usage and mass production offset printing.

    Most processes that depend upon true to life reproduction or accuracy will use more complex models with gamut’s that are closer to the visible spectrum.

    If you can comprehend that CMYK is not useful for many purposes but still remains a useful model for others then perhaps you might be capable of understanding that RYB can also be useful for some purposes.

    The mere fact that so many still use the RYB model make my statements self evident and undeniable. For your appreciation I quote but one definition of useful;

    “of practical use, as for doing work; producing material results; supplying common needs: the useful arts; useful work.”

    By that particular definition RYB is a useful model and will not cease to be so until among other things it stops ‘supplying common needs’.

    But do not let me stop you enjoying CMYK and its concrete yet still limited footprint.

    swestland responded:
    February 23, 2013 at 3:15 pm

    I don’t think either David or I “worship at the alter of CMYK”. For my part, I just think that CMY is a better choice of primaries than RYB. Simply, if one was to use three primaries (and no other colours) then you would get a much bigger gamut using CMY than using RYB. RYB would be quite a poor choice in fact. It’s not just scientists and technologists who think this – see this excellent video on you tube by Scottish Landscape Artist Scott Naismith about what is wrong with RYB – scottnaismith http://tinyurl.com/b2rcjyj

    I don’t think many artists use RYB practically; that is, they don’t create art made from subtractive mixtures of RYB alone. Because most – like Scott Naismith – know that if they did they would end up with with very dull (chromatically speaking) work.

    I agree that RYB could have its place but I have two issues with it. Firstly, its use in colour wheels that show the secondary colours as being really saturated when this does not happen in practice (this perpetuates the myth that you can make all colours with three primaries). Secondly, the preference of RYB over CMY on the basis that red and blue look more ‘pure’ than cyan and magenta (this perpetuates the myth that the primary colours are pure colours that cannot be mixed from other colours). Both myths are false of course.

    I really appreciate your contribution on the blog by the way. Part of the fun of colour is that there are lots of opinions and we don’t always all agree all of the time!

      DrShelp said:
      February 23, 2013 at 10:13 pm

      Quote: “if one was to use three primaries (and no other colours) then you would get a much bigger gamut using CMY than using RYB”

      In terms of the visible spectrum its a slightly bigger gamut with both models failing to achieve the same footprint.

      Quote: “RYB would be quite a poor choice in fact.”
      As pointed out CMYK is mostly suitable for reverse mapping pc/print and offset printing. “In fact” it fails for many practical applications, a model that cannot be relied upon for an application is hardly a better choice simple based on an increase in gamut size.

      Quote: “I don’t think many artists use RYB practically.”
      You would be wrong in that assumption, the majority of artist painters still use the RYB colour wheel for both teaching and for its intuitive benefits for colour mixing.

      Quote: would end up with with very dull (chromatically speaking) work.
      Your argument is becoming circular, the same is true of CMYK as pointed out many of the paint manufacturers have found they are unable to reproduce true to life swatches of their paint with CMYK because the gamut is too limited.

      Very few artist painters limit themselves to 3 primary colours of any model routinely for their work as they “intuitively” know the gamut is too restrictive. They may however limit themselves to selected colours to explore the style, effect and gamut range that can be achieved but not for the purpose of adhering to a particular colour model.

      Quote: ” I have two issues with it”
      Your “issues” I think are starting to look a little like a slavish adoration of a particular model.

      CMYK has its uses just like many other colour models but it also has many limitations. The danger here is in perpetuating exactly what you claim to be railing against i.e. encouraging a reliance on a colour model that in some circumstances is flawed and restrictive on the basis that it is “better” than another flawed and restrictive model because it has a bigger footprint.

      I see many of what I term as nouveau colour experts espousing their new religion and criticising others for not converting to CMYK, just like Christianity it works well for some in some circumstances but others prefer a different model for their needs such as Buddhism.

      Others feel that both models are an inadequate solution to their needs but may utilise some of the principles from both from time to time in different situations.

      Models can be useful and enriching provided those who use them do not become too fanatical, its always good to take a step back from your model and have some objective perspective on its deficiencies.

      Most of all its important to always bear in mind that ones personal experience of the world will tend to bias us towards a particular practising model and we need to leave room for the fact that others will find a different model a better fit for their application.

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