Saturday, June 12, 2010

Color Chart Exercise

This week's exercises call for exploring color mixing. Rather than the detailed manner in the style of Blue and Yellow Don't Make Green, these exercises are about lots of single mixes. I did get in a bit of the old style by doing two mixes, each in different tonal ranges.

I'll get to more of these, as well as some complementary gradations.

I have been thinking an awfully lot about browns and saturation in general. I guess browns can be categorized as low saturated yellow, oranges, and reds. But, then how does gray fit in? This morning I pulled up a bunch of my color charts into Photoshop and began drawing off the saturation, essentially bringing the chart down to a complete lack of color, only shades of gray.

So now what, I thought. Can lack of saturation be both brown and gray? As saturation decreased with yellow, the color slid off onto ochre. Excellent, I thought. Reduced saturation of yellow does lead to brown! But then I continued to decrease saturation and those ochers became gray! So now, I found reduced saturation of yellow led to gray.

I brought up all kinds of charts. Blues, greens, reds, and then some. Of course, as saturation decreased, every color finally became some tone of colorless gray.

So with all this, can I posit a hypothesis that browns are reduced saturation of yellow, orange, and red? There don't seem to be words for reduced saturation colors at the opposite end of the color wheel.

I do hope I'm making sense. I've spent a good deal of time thinking about this, messing about with Photoshop, and just staring at the multitude of browns and grays all about my yard.

The reason for all this commotion? One of my exercises calls from making brown by mixing primaries and then making gray by mixing secondaries. I've read in at least one other book the same thought. My feeling is that this doesn't really make sense. In fact, Exercise 24 has both browns and gray in the same mix. Example 17 is another good example.

If in general, secondaries can be mixed from primaries, then how can it matter? I wonder if I'm onto something here... Or am I just getting mixed up?


  1. John, re saturation and mixing. This is just my way of looking at it but maybe it will give a new light (ha ha) on the question.

    There are two things the eye sees: how much light is being received onto the retina (rod cells), and what wavelength(s) the light is composed of (cone cells). Saturation in Photoshop etc is the proportion of coloured light there is in the total light being perceived. If there is an equal mix of wavelengths, it's some sort of monochrome: white, or grey, or black, depending on how much light total there is. If there's more yellow wavelength, the grey will start to look ochreish, then yellowish, then bright yellow.

    Subtractive mixing means that browns and greys are not going to be brilliant colours because so much light is simply cancelled out by the mix of pigments absorbing it. Hence these colours are perceived as dark or dull. But the little light a brown is sending back is still coloured light, rather than evenly mixed 'white' light which is what a pure grey consists of. You can desaturate a rich brown and it will go greyer and greyer but the total quantity of light being sent back is the same -- it's just that the wavelengths are being mixed back into white light.

    A brown is not just a desaturated yellow or red -- it's a yellow or red which has had a lot of its reflective power stripped out by having complementaries added, so it's darkened. 'Light brown' is a broken-down warm colour with more plain white light added either in the form of body white or dilution so that more paper shows. More total light has been added but the eye still detects that a relatively high proportion of the total light is red/orange/yellow. It would become grey by adding more of the complementary which would cancel out yet more of the total wavelengths, ie blue.

    I think that's where the idea comes from that browns derive from mixing primaries, greys from mixing secondaries. Another way of looking at it is that a secondary plus its complementary primary makes brown (green plus red; purple plus yellow; orange plus blue) ... so long as there is enough red/orange/yellow in the mix. If you mix viridian (blue-green) with quinacridone (blue-red) you do not get brown because the blue dominates the final mix.

    When all three elements of the notional ideal primaries (red, yellow, blue) are balanced, you get grey. That is desaturation: the cancelling out of discernible colour wavelength without altering the overall light levels. You can do it by mixing secondaries but it depends how balanced the secondaries are. You already know that if you mix a yellowish green with a reddish orange you'll get a brown, not a grey, because orange and yellow will outweigh the little blue in the green. And a reddish purple mixed with a bluish green will give a violet grey.

    Greys are necessarily desaturated because no one wavelength really strongly dominates the total mix. But you know from BAYDMG how to mix secondaries that will defy any rule based on the erroneous idea that there is such a thing as a pure primary pigment colour.

    Oh dear; I have written a ramble. In short: you are right, 'browns from primaries, greys from secondaries' doesn't make sense for the good reason that you have already observed that the idea of a 'primary' is flawed.

    Think in terms of wavelengths and subtraction and you'll be able to predict any brown or grey that you want.

  2. Brilliantly illuminating, Katharine!

    Rods and cones eloquently setting the stage for the separation of saturation and subtraction.

    Saturation ranging from spectral to merely discernible with tonality holding constant.


    I can now visualize a model with a stream of white light (albeit a mere slice of the electromagnetic spectrum) bouncing off an object and being stripped of a portion of its energy, the object's subatomic particles vibrating with the power of wavelengths absorbed. Mix various objects (i.e. pigments) and their combined absorption subtracts a wider series of wavelengths. Electrons dancing wildly!

    Ha! Gray is just another color! It's just a condition of a certain distribution of subtracted wavelengths!

    But, gray is also the absence of the human apparatus to resolve reflected wavelengths into the perception of color. So during times of absence, only tonality remains.

    And, it seems, that gray is a color that we call not a color, even at high noon.

    This has been so helpful for me. Thank you for validating my assumption regarding source colors for browns and grays. But more so, thank you for leading me to think more clearly on the subject. You know, without you firstly recommending that I pick up Yellow and Blue Don't Make Green and my subsequent exercises, I would never have even considered challenging those brown/gray creation statements.

    As I was about to muddy the waters by suggesting that brown might really be conditioned on tone rather than saturation, my recent Munsell explorations came to mind. I am looking at an example of a brown--it is described as with both reduced chroma(saturation) and reduced value(tone, lightness). See, the example below the Chroma heading.

    An interesting way of describing color, isn't it. I was first led to Munsell after reading this article: which I have printed and read often.

    Thanks again, Katharine. This is all so fascinating! Now I must decide whether to do the dishes or mix lots of greens charts. There is a dishwasher on my near horizon...

  3. John, you are so kind to make my ramble sound illuminating. I have always loved BAYDMG for the physics and physiology underpinning the artist's technique.

    Someone told me one day that the highest concentration of the cone (colour) cells is in the centre of the retina, and the rod cells which pick up black-and-white, light-only stimulus are around the edge. He told me to look at the Pleiades (that little group of fuzzy stars, only 7 visible) straight on, and then to look at them a little sideways, with off-centre vision. Hey presto! -- more of them were visible when I focused the centre of my sight a little to the side.

    Our bodies are amazing machines governed by astonishing minds; isn't it wonderful learning about how art and science reach ultimately towards the same subject: how humans tick?

  4. Isn't the Munsell system interesting? There is a history to be written of how we have perceived colour through the ages. It's fascinating to look at medieval words for colour and to wonder what on earth people were seeing.

  5. It's all so truly fascinating. What can it be like for all the various creatures, each with their own spectrum range and interpretation? What's it like to see infrared or ultraviolet?

    I tell my blog readers to be sure to read the comments; they are often more interesting than the original post. It gets proved time after time...