What term refers to the chromatic purity of a color?

The term that refers to the chromatic purity of a color is "chroma." Chroma is a key concept in color theory that describes the saturation or intensity of a color, indicating how pure or vivid it appears. A color with high chroma is one that is highly saturated and appears more vibrant, while a color with low chroma may look muted or grayish.

In contrast, the other terms mentioned also pertain to color but do not specifically denote chromatic purity. "Hue" refers to the name of the color (such as red or blue), while "value" pertains to the lightness or darkness of a color. "Intensity," although related, often describes the brightness of a color rather than its chromatic purity specifically. Therefore, chroma is the precise term that captures the idea of how pure a color is.