Color wheels are fun, instructive, and beautiful. We owe their existence to Isaac Newton, as I discussed in a previous post. He realized that the extra-spectral colors—the range centered on magenta, between middle red and purple—could be used to connect one end of the spectrum of visible light to the other.
Extra-spectral colors do not appear when light passes through a prism because they are not produced by a single wavelength of light. But our eyes have the capability of combining multiple light wavelengths. When we observe a combination of the wavelengths at either extreme of the light spectrum—in such things as soap bubbles, oil slicks, hummingbird feathers, or bougainvillea flowers—our brains resolve what we are seeing into magenta and surrounding hues.
By using these colors to stitch together the extremes of the light spectrum, Newton created a circle in which colors face their complements—those that cancel them out to make white, gray, or black, depending on the medium—directly across the circle by means of a diameter through the center.
But Newton was primarily working with colored lightwaves. An artist’s mixing complements are different, due to the particular qualities of the pigments used in paints. “It is not possible to create a color wheel to summarize subtractive mixing complement relationships,” Bruce MacEvoy says, “because any single paint can be the mixing complement of several different paints on the opposite side of the wheel, and because two paints of the same color can have completely different mixing complements.” (Additive color begins with black and become lighter as color is added. Digital devices, for example, use electrical charges to cause red, green, or blue subpixels to glow, creating colored pixels. Paint, by contrast, can begin with a white page, which then progressively darkens as more color is added.)
Still, we can observe the visual relationships of paints around the color wheel, even if we have to rely on our experience with mixing paints to create true grays from them. So here we have the twelve points of the visual wheel of light, surrounded by chips showing the paints I currently have in my collection, placed in the appropriate position according to hue angle, as best I could determine it.
Hue is of course only one factor in how we perceive colors and their relationships. Physical paint qualities such as sheen, chroma (saturation), granulation, and value affect our perception of colors. Value refers to the amount of black or white in a color. It is primarily variations in value that create the striking apparent alternation of light and dark in the northwest corner (deep yellow through red orange) of the outer ring of this wheel (see the detail at the top of this post). To me the effect is like a succession of doors off a central courtyard, some bathed in light, others partly or deeply shadowed.
I created the inner circle in Photoshop. It represents the ideal conceptual color of twelve points on the color wheel. The primary triangle points on the inner circle are yellow, magenta, and cyan. Each is 100% of its color in CMYK mode. A secondary triangle in the inner circle is made up of red orange, blue violet, and green. The remaining six points are the tertiary colors, deep yellow, middle red, purple, middle blue, blue green, and yellow green. (K, or black, was always set to zero.) I’ve followed the naming convention used in Bruce MacEvoy’s handprint.
In the inner circle, accordingly, secondary colors are 50% each of two primaries. Tertiary colors on 75% of one primary and 25% of another—for example, “red orange” is 50% yellow and 50% magenta, while “deep yellow” is 75% yellow, 25% magenta.
Having produced the inner ring in this way, I then printed the result on watercolor paper. Then, after painting the outer ring, I photographed and uploaded the result. This is an imperfect process, so the colors may shift on your viewing device, particularly since there is a range of color settings on different devices.
For any particular painting I typically use only a handful of colors, but this wheel shows all the ones I have available to choose from. Most artists favor the deep yellow through red orange range in their palettes, and such is the case here. It is especially so because I am fond of earth colors. I began with Winsor & Newton earth colors, which have proved to be workhorses, but I added many more from both W&N and Daniel Smith.
The physical wheel that I made on watercolor paper includes a pigment identification reference. There is also an Excel document that shows the hue angles and ratings for transparency, staining, granulation, and lightfastness for each—a sample section appears a few paragraphs up. Below is the complete wheel including text, and below that is a link to the Excel file as a pdf, which you should be able to download. Happy painting!