Hue, value, chroma: Here we see two different hues of violet with different levels of chroma.
What is the chroma color theory?
In color theory, chroma refers to the degree of vividness of a color, or how pure it is compared to its representative on the color wheel. It can also be called saturation, or color intensity. Understanding chroma is essential for creating the Munsell color mixing chart, which relies on a 16-step chroma sequence.