Color occurs when light in different wavelengths strikes our eyes. Objects have no color of their own, only the ability to reflect a certain wavelength of light back to our eyes.
Hue is somewhat synonymous to what we usually refer to as “colors”. Red, green, blue, yellow, and orange are a few examples of different hues. The different hues have different wavelengths in the spectrum.
Saturation is an expression for the relative bandwidth of the visible output from a light source. In the diagram, the saturation is represented by the steepness of the slopes of the curves. Here, the red curve represents a color having low saturation, the green curve represents a color having greater saturation, and the blue curve represents a color with fairly high saturation. As saturation increases, colors appear more “pure.” As saturation decreases, colors appear more “washed-out.”
Informal:
Intensity
Intensity, also called chroma or saturation, refers to the brightness of a color. A color is at full intensity when not mixed with black or white – a pure hue. You can change the intensity of a color, making it duller or more neutral by adding gray to the color. You can also change the intensity of a color by adding its complement (this is the color found directly opposite on the traditional color wheel). When changing colors this way, the color produced is called a tone.
Informal: Adding a element of light that adds to a composition.