Colorfulness

Colorfulness, chroma, and saturation are important ways we describe how bright and lively colors appear to us. They help explain why some colors look more vivid and rich than others. Colorfulness is how much a color stands out from gray, white, or black. It depends on both the color of an object and how strong the light shining on it is. The brighter the light, the more colorful the object usually looks, unless the light is extremely bright.

Chroma tells us how different a color is from a gray of the same brightness. It focuses on the object’s own color properties. Saturation, on the other hand, describes how much a color looks “pure” compared to its brightness. An object’s saturation stays about the same no matter how strong the light is, unless the light is very bright.

These ideas help scientists and artists understand and measure colors more exactly. They are used in systems like the Munsell system to describe colors in a way that matches how we see them. Whether you are painting a picture or studying light, knowing about colorfulness, chroma, and saturation can help you see the world in a whole new way.

Chroma

See also: Psychophysics

Chroma is a way to measure how strong or weak a color looks. It tells us how much of a color there is compared to a neutral shade like white or gray. In some systems that help us understand colors, chroma shows how much of the color stands out.

When we use special tools to study how our eyes see colors, chroma can help us describe colors in a way that matches what we actually perceive. This makes it useful for understanding how colors appear in different lighting or on different surfaces.

Saturation

Saturation tells us how pure or strong a color looks. A highly saturated color is very bright and pure, like the light from a laser. If we make a color lighter or darker, its saturation goes down. We can also make a color less saturated by adding white, black, gray, or its opposite color.

There are different ways to measure saturation. In some systems, it depends on both the color’s strength and its brightness. In other systems, like HSL, saturation can stay high even when the color is very light or very dark.

Excitation purity

The excitation purity of a color measures how far a color is from a neutral white color. It is calculated by comparing the position of the color on a special diagram to the position of the white point and the farthest point on the diagram with the same dominant wavelength. This helps us understand how "pure" or intense a color appears compared to white.

Different systems for describing colors can give different results for excitation purity, but they all aim to show how much a color stands out from neutral white.