Neutralizing Colors Efficiently

I keep hearing art instructors tell students to neutralize saturated tube colors with their compliments. To neutralize Red, use the ‘compliment’ Green, for Orange use Blue, and Purple will tint Yellow. There are problems with this approach:

  • True compliments that neutralize colors are not what is popularly asserted. As I’ve written elsewhere (see Software Color Doesn’t Agree), what really neutralizes a red is not green, but a teal. Orange is neutralized somewhat greenish blue, and yellow by a somewhat purplish blue, as this chart illustrates (number correspond to hue numbers in the HSL computer color space):

neutral-blends-x

  • One of the reasons why the conventional advice evolved is that to the naked eye, it looks like the traditional compliments do neutralize. Take a Cadmium Red and mix it with Viridian and it will look neutral. So there is some truth to it, but it’s not a perfect neutralization. Keep this mind:
    • The blended color is not really a true compliment. It might not even be the hue of its label; it’s a tint of a warmer hue. The color you’re mixing with is not a tint of the hue you’re thinking of. That’s because hues shift towards perceptually cooler temperature as they are tinted. Therefore, a dark green like Viridian would look warmer if fully saturated and brighter.
    • Tinting with the ‘compliment’ means that a certain value (aka brightness) inherent in the added color is forced on the mixture, and it’s likely not the value you’re targeting. It’s very hard to mix traditional compliments for lighter value ranges, for example. If you want to neutralize a pink, you have to find a really light green. In practice ­one ends up mixing in white, and at that level of tinting, you can’t really discern the true hue anyway. So as long as it is close to the cool or warm we’re looking for, we’re satisfied.
    • Phenomena in perceived colors are projected into the color mixing process, and this doesn’t help. It’s true that with a cool light, the highlights will obviously be cool, and the shadows will look warm. We tend to think the light hitting the shadows is of a complimentary hue to the one hitting the lights, especially as the light is saturated. We get this phenomena in the extreme with sunsets – the very warm yellow setting sun will light up warm clouds where it hits, and the very same cloud will look blueish grey where the light does not hit. The color of the form is the same on the light and dark sides, but the complimentary highlight/shadow phenomena of light makes them look very different. Just because that’s how color is perceived doesn’t mean that’s how it has to be mixed!

Despite these tendencies, professional artists will arrive at good results, not because they are literally following the traditional compliments theory. Rather, through experience and a lot of mixing, they get what they want, and chalk up any deviations to the inherent ambiguity of artists’ tube colors. One manufacturer’s Brown Pink is a lot more orange than another’s. Not everyone can tell the temperature difference between a maroon and a scarlet.

In fact, we would benefit from an objective hue numbering standard for hue colors. For example, regardless of the traditional name, an additional hue number would be printed on the tube, along with some saturation and brightness rating. This could be mapped to a computer model, like Hue Saturation and Brightness (HSL). But that’s a topic for another day.

So how can we more efficiently mix the greys we’re after? The answer is actually straight forward, but it requires throwing out another rule that many painters who ‘tint with compliments’ swear by (including the Impressionists): don’t use black because it ‘muddies’ colors. Let’s now also dispel this scare tactic – a ‘muddy’ color is just another grey that finds itself in the wrong place. Any grey can be a muddy color in a given context. If you’re painting a sepia portrait, warm greys are wonderful. If you’re painting portrait in a cool light, the same grey will look muddy.

It’s ironic that artists who loathe black use white quite liberally. While both black and white are neutral colors and technically both have the capability of ‘muddying’ colors, artists don’t dump on white because at the lighter range, we’re much more forgiving of ‘wrong’ greys. We actually don’t see ‘muddy’ whites. Let’s call a spade a spade: all tints are greys, and ‘muddy’ colors are simply greys out of context.

So the problem is not about having black on your palette; the problem is with not understanding how to properly tint colors. This brings us back to two areas we touched on: hue shift, and target brightness. Hue shift is simply the phenomena that colors will look cooler when tinted. Take Vasari Ruby Red, for example, mix it with various shades of grey, and it will look pink in the lights and lavender in the darks (as shown here).

RubyRedGreys

Take a lemon yellow, mix it with black, and you’ll be convinced that there is a warm green in the mixture (but there isn’t).

YellowGreys

It’s valuable to know the expressive range of your colors on their own, and how they change with pure greys. This will simplify the thought process and let you focus on other challenges in the work. Develop a sense for that color’s hue shift on tinting. The best way to do this is to simply mix up a range of light and dark greys from black and white, and then mix your tube color into each. This will take some time, but if done on some canvass sheets, you can actually pin them to a cork board on your wall for reference. That way, instead of winging it every time guessing at the hue you’re looking at, you can instead compare it with your wall swatches and then pick the proper tube color and know which value of grey to mix it with.

What I’ve touched on here is a method of mixing that relies on using true greys – and this means use black! Let’s face it, if the traditional method of using compliments to neutralize is true, then exactly half way between the two colors is a perfectly neutral grey that is indistinguishable on its own from a mixture from black and white. As you know, black and white are cheaper than other pigment colors, so why waste all that money having a perfectly complimentary tube color for every color you intend to use? That’s anyway not possible because pigments don’t align neatly with the saturation and value of a given tube color’s perfect compliment. You’d also have to have many more colors that would otherwise be the case if you just mixed to grey. So take the mythology of compliments out of your mind for color mixing. Put that traditional color wheel in the bottom drawer. There is certainly a place for oscillating between warm and cool colors in a painting for interest. To achieve that level of visual excitement on the canvass, you can just mix each color directly, and apply it. Simulate the complimentary effect of light in the image, not in the mixing process. You’ll preserve visual interest while conserving on precious colors, and mix faster once you know your colors native potential.

Copyright © 2015 Roy Zuniga

Software color doesn’t agree

Artists face challenges mixing colors, especially in portraits where it is critical to get the subtle color of cheeks, lips and hair just right in relation to each other as the form of the head turns. Because of the immense variation in lighting and coloration from person to person, useful skin colors do not come straight from a tube of paint. Skin tones are never a fully saturated red or orange. Rather, they are lighter tints or darker shades of colors, meaning that each tone is a lighter or darker version of the well-known hue, albeit at a lower saturation and different value.

The skilled artist needs to be able to mix any color at will, and to do so we have been taught to identify the hue, find the corresponding tube color, and mix a tint. I call this the Hue-to-Tint method. It depends on understanding the traditional artist’s color wheel because when you know a colors compliment, you can generate a tint by mixing the compliment (or lighter and darker tints of that compliment as necessary). For example, if you identify a light pink cheek color, you go for a cool red, which will be darker, and both neutralize and raise the value with a light green. 

That’s the theory anyway. In practice it’s much harder because the tube colors don’t match the chromatic color wheel on either side, and there ends up being a lot more experimentation and happy or unhappy accidents along the way.  Being a technologist I turned to my computer to see if I could generate more helpful color charts to aid in color mixing. What I ended up discovering was a better method of mixing I call Tint-to-Hue method, which I’ll explain a subsequent topic. First some more context.

Having been trained as an artist in the traditional color wheel model that uses the three ‘primary’ colors, i.e. Red, Yellow and Blue to mix the ‘secondary’ colors, i.e. Violet, Orange and Green, as well as other ‘tertiary’ colors, I decided to blend these colors in my computer to get neutrals. The traditional theory states that when you mix compliments together, they neutralize each other, resulting is a hue-neutral grey in the middle (i.e. zero hue saturation grey). We learn this in art class and take it for gospel.

When mixing complimentary tube colors, say a red with a green, we therefore expect to get a neutral. In practice, I would get a tint since any mixture is more neutral than the original colors. I assumed the color theory was at work here, not realizing that mixing tints is not the same thing as getting a pure neutral grey. Because tube colors rarely come as pure and saturated as what we find in color wheel charts, it’s hard to discern a problem with the theory. If we don’t get a true neutral, we just assume it’s a function of the offset of the tube color from the theoretical color.

I took the traditional theory for granted in my painting and would often pull the compliment of a color to neutralize it. By not using black or a grey as the neutral to mix with, the resulting tints are more interesting than just adding black and/or white to the mix anyway. You get a richer effects, analogous to chords in music where you can ‘hear’ several tones at once. Thus the lack of true neutrals in mixing traditional compliments actually can be artistically interesting – in some cases a happy finding. So if the results are good, never mind the means. So we shrug off any theoretical differences when looking at a successful work of art. The problem is that accidents are very repeatable, and the next round may be less successful.

Any artist who has tried to mix colors know that by trial and error, and sometimes with great frustration, we eventually get something believable. It is an axiom among seasoned artists to say ‘the color doesn’t have to be 100% accurate; it just has to be believable.’ In fact, take a look at many of the master works and you’re see that while the colors are believable within the world of the work, they are not accurate. So the professional learns to mix progressions of colors that are believable, and then the traditional color wheel and its theoretical neutrals are just guidance; it’s not critical they be true. In other words, the seasoned artist creates a personal mixing methodology that works, and then the correspondence to a color wheel theory is irrelevant (unless of course, they have to teach it).

Artists respond and compensate on the fly. We are not scientists. We live with paradox, compensate with contrasts, all of which contributes to artistic impact when done skillfully. We are masters of compensating for inaccurate color. Said another way, accuracy is not our measure; artistic impact is. And you can have great impact with inaccurate color. The few times I’ve watched masters at work, the really interesting things they do is ineffable. I learn more by watching them paint that listening to what they say.

So when I got scientific with color on my computer’s color picker, expecting the traditional color wheel to be validated, I was surprised. The traditional color wheel’s compliments – like green and red, orange and blue, yellow and purple – did not in fact neutralize.

As I played around with a graphics program (Adobe Illustrator), I created two colors and had the software blend them from left to right. For example, orange and blue are compliments in the traditional model. So mixing them should produce a few less saturated tints and a neutral in the middle, right?

Wrong. The color theory taught for generations was not being validated by the software:

Image

To my chagrin, the middle colors (from left to right) were not the neutral I expected. The tints were interesting enough, but they were not really something I felt I could predict logically. For example, in the blue-orange blend, the middle color looks like a dark violet, which we should be getting by mixing red and blue instead. That was confusing. The red-green blend looked a little more predictable, i.e. a warm green. But yellow and violet were unexpected – we should be looking at something more greenish, as you do when you mix yellow with black?

‘Hmmm,’ I thought, ‘maybe paint mixing artists work in another color space?’ What color space does my computer have?  Knowing a few things about graphics programs from my previous life as a graphic designer, I used the Hue-Saturation-Brightness (HSB, also known as HSL) model in order to explore the numbers of the hues. I soon realized that increments of 30 gave me all the primary, secondary and tertiary colors in the traditional model. Since the hue numbers go from zero to 360, it became obvious that the computer also has a color circle (zero and 360 are equivalent, i.e. red). Logically it would follow that the colors that are 180 degrees from each other would be the compliments. For example:

Image

Is this true? Let’s blend these colors and see if they result in neutrals:

Image

To my delight, the middle tones were all a perfect zero-saturation grey, meaning there is no saturation in them. The computers compliments did in fact perfectly neutralize each other. However, the HSB compliments are decidedly not the traditional compliments. At this point it was clear that the software model confirmed the theory that compliments neutralize each other. However, the definition of the complimentary colors themselves was decidedly different than the traditional model. Why are the two models so at odds with each other? Are they inherently different realms, or is one of them wrong? What did the software engineers know that the artists didn’t pick up on?

The answer to the last question will make for some interesting research. Who came up with the first color wheel decades or even centuries ago, before the time of software? Was it driven by the mathematics of light spectrum, or by experimenting with mixing pigments and eye-balling the results? I have a hunch that hue-shift on tint may have had something to do with the state of the traditional model.

If the old model is broken, why aren’t our modern masters complaining about it? I have a hunch about this one: masters get so good at color mixing it becomes instinctive. They reach for one color or another based on what they are seeing, not on what they are thinking about seeing. Like athletes who just act to make the crucial shots, instead of thinking about them.

In other words, color wheels are for newbies, training wheels that have little to do with the actual experience of creating master works. The masters ‘just do it’ until it looks right. They get to know each color and how they blend and tint. Theory is too much mental work when you know how to get the desired result! It also helps to note that the old theory isn’t completely broken. As illustrated above, you can get some very interesting tints by mixing colors that are not mathematically speaking true compliments.

Okay, so the computer thinks differently. When has that ever influence how artists think? Should it? Moreover, can it be proven with actual color mixing? (We’ll experiment with this question later.) Well, being an artist myself, I can attest that it matters a lot because a solid methodology can greatly simplify the color mixing process. It can also save us time and money. We can drive practical lessons from the computer model, which, after all, is based on the same light spectrum that governs our pigments. Fewer colors to mix means more time painting and fewer materials used, as we shall see with the Tint-to-Hue method. A consistent methodology also contributes to sanity because no, dear student, it’s not that you don’t get it. It’s possible you were taught an inaccurate color wheel in the art books.

 

Copyright © 2014 Roy Zuniga