Definition - What does Color Saturation mean?
Color saturation refers to the intensity of color in an image. In technical terms, it is the expression of the bandwidth of light from a source. The term hue refers to the color of the image itself, while saturation describes the intensity (purity) of that hue. When color is fully saturated, the color is considered in purest (truest) version. Primary colors red, blue and yellow are considered truest version color as they are fully saturated.
As the saturation increases, the colors appear to be more pure. As the saturation decreases, the colors appear to be more washed-out or pale.
Techopedia explains Color Saturation
Color saturation determines how certain hue will look in certain lighting conditions. For example, a wall painted with a solid color will look different during the day than it does at night. Because of the light, the saturation of the wall will change over the course of day, although it is still the same color. When the saturation is zero, what you will see is a shade of gray.
Brightness of the color is controlled by the amount of the white in the hue.