While most people use the word "color" to describe visual appearances or differences in the reflective qualities of objects they see, many factors are involved in the actual experience of viewing colors. We often aren't aware of the reasons we respond or fail to respond to colors.

For the majority of us who can see an average range of colors, we normally see colors in terms of hue, saturation, and value (HSV).

Hue correlates with the color's position on the visual spectrum, and is associated with a color's warmth or coolness. Most people think of red to orange to yellow colors as "warm" colors. In studies, subjects surrounded by red colors have experienced increases in body temperatures, heartbeat, and blood pressure. Yellow is thought to produce higher mental activity levels with less stress than red. In contrast, deep violet, blue, and green colors typically produce a sensation of peacefulness, relaxation, or calmness in test subjects. Some colors are on the borderline; a red/violet or a yellow/green color can take on different temperatures depending on its surroundings or the pigments used to mix it.

Saturation (sometimes called chroma) refers to the intensity of a hue. While a hue in its unadulterated state is a pure color, with a saturation of 100%, if it is mixed with black and/or white, or another color, its saturation or intensity as the original color is diminished. Mixing a hue with black produces a shade; mixing it with white results in a tint, and a mix with a gray of a similar value produces a tone of the original hue.

Mixing a hue with its opposite on a color wheel will diminish its intensity. Imagine mixing a large amount of red paint with a small amount of its opposite color green paint; the resulting color will be a less intense and darker red. Continuing to add green to the red will result in a darker and browner color. If the same red is mixed with white pigment, a pink color or tint will result. If the same red is mixed with black pigment, a darker maroon red or shade will result. In all these examples, the saturation of the original red color has been diminished.

The value (sometimes called brightness or lightness/darkness) of a color is defined by how much total light it either absorbs or reflects back, regardless of its color or hue. Every color or variation on a color has a specific value, based on the total amount of light it reflects.

Value is not specifically a color issue. Extremely effective designs can be created with black, white, and gray scale tones using no color at all. Often our initial reactions to a design are based on how we unconsciously perceive the value key, or light and dark composition of the design. We often experience reactions to values in a design, even a very colorful one, without realizing that the color changes in the design are also creating a mood based on its equivalent value key. Gray scale value considerations and value keys will be discussed in detail in a future module.

Value scales for the printing process range from 0% absorption of light (white) meaning that 100% of the light is reflected back, to 100% of absorption (black), or no light reflected back. A 50% value is a middle gray value on the scale, meaning that roughly 50% of the light is absorbed and 50% is reflected.