What color is this?

This is a painting I did a few years ago (click on the picture for an enlarged version). The palette is fairly limited, almost monochromatic.

All the colors reside within a narrow 75 degree area of the 360 degree color wheel - between hue 25 (orange) and 100 (yellow-green), approximately. Yet, the picture seems to have blues, greens, reds, even purples.

This is because, as with value, our visual system expands the existing range of colors to create the appearance of a full spectrum. That is, the bluest color in the image reads as blue, the greenest reads as green, etc. But what is the “bluest” color, if no color actually is a blue hue?

Plot out a few of the painting’s colors on a simplified color wheel and you’ll see the answer. The colors from the painting's palette form an elliptical ring – their own little color wheel, within the narrow wedge of the standard wheel. The center of this little ring is not truly neutral gray, but it is what will read as neutral (white, gray, black) within this image. The color (which actually is very close to a neutral gray), reads as blue within this image, and so on.

Though this works with every section of the color wheel, it’s most effective within the warm or “earth” tone area (oranges, browns, warm yellows, as in this image) for reasons we’ll discuss later.

This analysis demonstrates two important points about color: first, color is relative. We can’t really tell what a given color is by looking at it. Second, very limited palettes can produce color schemes that are very harmonious while at the same time seeming to employ the full spectrum of hue.

Read the CG Society feature article on how this painting was made