Mixing paints is simple if you understand how pigments work.
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| Tilt-a-Whirl, by Carol L. Douglas. Painted plein air. |
Let’s start with some simple review of the color wheel. Red, blue and yellow are the primary colors. Across the wheel from a color is its complement—the color that completes the circle. The complement of a primary color is always a secondary color. A secondary color is one made by mixing two primary colors.
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| The color wheel. |
In theory, you can paint with just four pigments: red, blue, yellow and white. For beginning painters this is sometimes a good idea, because it’s the fastest way to learn color management in a hurry. It simplifies the thought process so you have only one decision to make at a time, and it is easier to get a more unified color scheme.
But there is a big limiting factor, and that’s the impurity of pigments. They all have overtones that muddy them up in certain mixes. That’s why your local paint dealer uses many, many more pigments than just red, blue, and yellow.
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The takeaway lesson here is that different pigments may look similar out of the tube, but they reflect light (and thus mix) very differently. From Scientific Examination of Art: Modern Techniques in Conservation and Analysis, 2003, National Academy of Sciences.
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Claude Monet’s palette shifted over time, but included these paints:
- Chrome yellow
- Cadmium yellow
- Viridian green
- Emerald green
- French ultramarine
- Cobalt blue
- Madder red
- Vermilion
- Flake white
- Ivory black (before 1886)
These are sets of paired pigments. That means he has a warm and a cool of each color. Gamblinmakes a modern version of this impressionist palette. It includes:
- Cadmium yellow light
- Cadmium yellow medium
- Cadmium red light
- Alizarin permanent (actually anthraquinone red)
- Ultramarine blue
- Cerulean blue hue (actually phthalo blue plus white)
- Viridian
- Ivory black
- Flake white replacement (or titanium white)
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| Paired primaries. |
Both Monet’s and Gamblin’s palettes are paired primaries plus green, white and black. I use paired primaries as well, omitting the green but adding in some other earths. (Here are my supply lists for oils, acrylics, and watercolors.)
The distinction between warm and cool colors has been important in painting since the Impressionists. Warm colors are said to be hues from red through yellow and cool colors are said to be the hues from green through violet. Each hue around the color wheel also has a warm and a cool version.
There’s no factual hot or cold point because this is a poetical description that works, rather than a scientific fact. Much of what we believe about the psychology of color is hocus-pocus, but it’s true that if the light is what we call “warm,” the shadows are what we call “cool,” and vice versa.
When we say that lemon yellow is cooler than cadmium yellow deep, we mean that if you are trying to mix a greenish yellow, you’ll get a clearer shade with the lemon than you will with the cadmium. The warm-cool language is just a convenient way of saying that.
Different pigments may look the same when squeezed out of the tube, but there the similarity ends. Pigments are impure, and you have to learn and work around those impurities.
Today’s lesson is an experiment in working through those color shifts. I want you to make the above color chart, using three sets of paired primaries:
- Prussian blue—Ultramarine blue
- Quinacridone violet—Cadmium orange
- Indian yellow—Lemon yellow
The purpose of this exercise is to understand how paired primary pigments work together, so that you can make neutrals when you want them, and avoid mud when you don’t.
Draw the chart onto a canvas, and then mix across and down for each square. The left column and the top row should be pure pigments. Fill it in, then, just like the multiplication tables of your youth. For example, the intersection of cadmium orange and ultramarine blue should be a 50-50 mix of those two colors.
Unless you’re painting in watercolor, the result should be opaque.
Let me know if you have any questions. And have fun!