Color is a perception of the world around us based on the type of light energy that is bouncing off of objects and then traveling into our eyes. These beams of energy activate three levels in our eyes: the amount of red, the amount of blue, and the amount of green. The different combinations of these three values result in us humans seeing different “hues”.
The three components of color sensation are hue, tonal value (also referred to by tone, value, or intensity), and saturation. (also referred to by brightness or vibrancy)
Hue perceptions are determined by the dominant wavelength of light reaching the observer. Hues come in varieties such as violet, blue, cyan, green, yellow, orange, red, magenta, purple, and blue/violet
Warm & Cool Colors
Hues leaning towards yellow-red are often referred to as warm, while hues leaning towards blue-green are referred to as cool.
Saturation is the degree of wavelength dominance present in color observation. A high saturation value means the light has a very narrow range of photon strength and the resulting color perception is vibrant. The term pure color is used to describe color sensations very high in saturation; "pure" refers to the number of different wavelengths present being as low as possible.
Dull means low in saturation, or desaturated, and these colors appear washed out. Achromatic grays have a minimum saturation value.
Tone describes the overall intensity; how dark or light. This component is a percentage scaler from minimum (black for all colors) to maximum, the lightest the hue can be–or lack thereof depending on the saturation.
Tonal luminance is sometimes separated from the other two variables–hue and saturation–which combine to become known as chromaticity.