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

Tinting with color recursion

To mix a tint you have a couple of choices. You can sneak up on it (as described in the ‘Tinting the hard way’ topic discussed elsewhere), or; you can identify the tube color based on the hue in the Tint-to-hue chart, or; you can mix colors that are 60 units apart on both sides of your target color. The last is color recursion, as illustrated here:

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Here’s a circular view of the same phenomenon:

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In this case, the intermediate hues aligned with the expected midway numbers between our primaries. The other interesting part is that the saturation went down by a half on all of them. This means that a blend between two saturated colors results in a saturation half-life. You can mix the product of the mixtures again and the results recurse back to the original hues, albeit with even lower saturation and value:

Image

If this persisted with blends of the intermediates recursively, it should result in neutrals (close to zero saturation), as this recursive blend diagram shows:

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Finally, taking the exercise even further, you can get a lot of interesting colors:

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copyright (c) 2014 roy zuniga