


normal saturation. notice how the colours are fairly muted
Colourfulness is the difference between a colour against grey. Chroma is the colorfulness relative to the brightness of another colour which appears white under similar viewing conditions. Saturation is the colorfulness of a colour relative to its own brightness. Though this general concept is intuitive, terms such as chroma, saturation, purity, and intensity are often used without great precision, and even when well-defined depend greatly on the specific colour model in use.
A highly colourful stimulus is vivid and intense, while a less colourful stimulus appears more muted, closer to gray. With no colourfulness at all, a color is a “neutral” gray (an image with no colourfulness in any of its colours is called greyscale). With three attributes—colourfulness (or chroma or saturation), lightness (or brightness), and hue—any colour can be described.