Color Theory Part 1: The Color Wheel

Color theory is the practical guide on color mixing and color combination.  This is the first on a multi-part series about color theory. In this first article, you will learn about color theory as it applies to the color wheel and its definitions.

It is important to know that the foundations of color theory were based around “pure” colors.  Practical applications on mixing these colors will lead to different and sometimes disappointing results.  Conventional wisdom tells us that mixing red and blue yields purple, but in reality the color will be dull and muddy, not the rich purple you were expecting. The reason for this is most of the color pigments in modern paints are not pure, and some lean more to the “warm” or “cool” side of their spectrum.

Why is Color Theory So Important?

Almost every time you hear about art someone is talking about color theory.  So why is it so important?  Color plays a very important role in our world, even without our realizing it.  Humans are visual animals.  The visual cortex is the largest area of the human brain.  Over 90% of the information entering the brain is visual, and it is the primary way that humans interact with their world.  Color affects our moods, appetites, and how we feel about people and places.

Color is a very important component of graphic design.  Colors have prescribed meanings, and the choice of color affects the mood and meaning of the final product.  Both fine art and design rely heavily on colors to convey meaning and mood.  Interior designers rely on color theory in selecting decor and colors of paint.  They need to make sure the colors are harmonious and not overwhelming.  Graphic designers use color in logos, websites, marketing, and advertising.  Fine artists use color to set a mood in their paintings.

In this series of articles, I will discuss color theory.  It will cover basic definitions, such as color mixing, the color wheel, and color properties.  The next article will cover color psychology, which is the way colors make us feel.  The third article covers color harmony, which is combining two or more colors to create a scheme.  The fourth article is about color relativity, which is the way colors affect one another.

Additive vs Subtractive Color Mixing

There are two main ways colors can mix: Additive and Subtractive.

Additive color mixing is what happens when different colors of light mix.  All three primary light colors (in this case, red, green, and blue, or RGB) combine to form white. This is how your computer monitor displays color. Red and green light “mixes” to create yellow, red and blue light mix to create magenta, and blue and green light mix to create cyan. This is also how your eye sees color.  Animals perceive color when light reacts with the cone cells in the retina of the eye.  Humans and other primates have three cone cells: red, green, and blue.

Subtractive color mixing is what happens when you mix pigments, such as paints or inks. This is used most often in color printing, where different amounts of cyan, yellow, and magenta (CMYK) are mixed to produce all the colors. The subtractive method also includes the traditional red-yellow-blue (RYB) of traditional painting, although mixing all the colors in the RYB scale will yield not black, but brownish grey.

For the purpose of this article, we will only focus on subtractive color mixing in traditional painting, which uses red, yellow, and blue (RYB).

Color Wheel

The Color Wheel is the representation of the primary, secondary, and tertiary (or more) colors. These can be really simple or very complex.  The color wheel that is most familiar is a circle or ring, with a gradient of fully saturated colors on the outside of the wheel.  This is a good basic representation of color theory, and one I will use here.

The earliest mentions of color theory first appeared around 1435 by Italian artist and philosopher Leone Battista Alberti, and around the same time by Leonardo da Vinci. More in depth color theory principals as well as the first color wheel was written by Sir Isaac Newton in his book Opticks, 1704.  The first true color wheel as we know it today was created by German poet Johann Wolfgang von Goethe.  It was based on the idea that red yellow and blue are the primary colors from which all other colors are created.

Although only twelve basic colors are described here, in reality the color wheel is an infinite gradient between all the colors, as well as black, white and gray.  There are, of course, colors beyond tertiary, and are the result of gradual mixing of two colors. The Munsell color system represents hue, value, and chroma of all colors in a three dimensional color sphere, and is more comprehensive than the traditional color wheel.

Primary Colors

Primary Colors

The primary colors are the colors that are considered to be the foundation of all colors.  In this case, we are talking about red, yellow and blue.  These colors theoretically be mixed to create all the other colors.

Secondary Colors

Secondary Colors

Secondary colors are created when mixing two primary colors.  These are orange (red-yellow), green (yellow-blue) and purple (red-blue).

Tertiary Colors

This has two definitions, depending on which source you use. The usual definition of tertiary colors is mixing two colors directly adjacent to each other on the color wheel to create an “in-between” color.  These are vermilion (red-orange), amber (orange-yellow), chartreuse (yellow-green), teal (green-blue), violet (blue-purple), and magenta (purple-red).

The second definition of tertiary colors is  mixing two secondary colors.  This usually results in a brownish color. For example, mixing purple and orange, or purple and green, or green and orange.  Mixing colors that are complementary (opposite of each other on the color wheel) will result in brown.  Example: red-green, yellow-purple, orange-blue.

Tint, Shade, and Tone

Tint, Tone and Shade

Colors can be modified also by adding grey, black, or white.  A tint is when white is added to a pure color, making it lighter. A shade is a pure color with only black added, which makes it darker.  A tone is when gray is added, making the color darker and less saturated.

Color Properties: Hue, Value, Chroma

Hue Value Chroma

Hue Value Chroma

There are three other ways of describing color, and these terms are usually reserved for graphic design and computer colors, and are used by the Munsell Color System. This color system uses a three dimensional representation of colors based on these values. Hue is the term used for the color “family”, such as red, yellow, green, and blue.  Value is the term used for how light or dark the color is. Chroma, or saturation, refers to how intense or “pure” the color is.

Color Values

Color Values

Color Values

Colors all have a value, that is, the darkness or lightness of the color.  You can judge a color’s value by converting it to grayscale.  On a pure grayscale, white is the lightest value and black is the darkest value.  Pure colors also have a value.  Yellow has the lightest value of all the pure colors, and blue is the darkest.

In the graphic above, there are two rows.  The top row has 6 squares of the pure colors: red, orange, yellow, green, blue, and purple.  The bottom row is the grayscale conversion of those colors. Using this, you can see the true values that these colors have. In computer image editing programs, grayscale ranges from black at 0% to white at 100%.  The yellow converts to a gray that is close to 90%, orange and green both convert to grays that are about 60%, red converts to 30%, the purple converts to about 15% and the blue is about 10%. You can use This Tool to get a RGB conversion of a color.

Many painters use grayscale conversion of their reference photo to see the true values, that is the darkness and lightness in relation to each other.  For most paintings, getting the value correct is more important than matching the exact hue of the color.  This is how artists who work in abstract color decide which colors to use.  Lighter areas can be represented with yellows and oranges, and darker areas with blues and purples.  I have used an example of my colorful cat painting “Anticipation” above, and its grayscale to the right.  The reference photo is below, in real colors and grayscale.  In the painting, the colors are all over the place.  But when converted to grayscale, the tones match those in the reference photo below.

All Articles in the Color Theory Series

Further Reading: