A color proof on a computer monitor, also known as a soft proof, is based on the "additive color process", where all colors are formed with the additive primary colors, red, green, and blue. The soft proof can be useful during the design process, but it is of very little use as a tool to match with the colors attained through the printing process, whether it be on a printing press or on computer printers. Printing output utilizes the "subtractive color process", with cyan (C), magenta (M), yellow (Y), and black (K) as the colors used to form the range of color. Because of the differences in the color gamut between the additive process and the subtractive process, accurate color proofing, using only the computer monitor, is not effective.

The additive primary colors red, green, and blue, with the secondary colors that are formed, cyan, magenta, and yellow.	The subtractive primary colors, cyan, magenta, and yellow, with the secondary colors that are formed, red, green, and blue.

To be able to view the most accurate color on your monitor, it should be located in a windowless area which is surrounded by a low level of neutral light. It is also helpful if the color of nearby walls is of a neutral gray which will aid in preventing any visible colors surrounding the monitor to influence color vision. A hood that fits over the front of the monitor could be added to keep the ambient light from changing your perception of color.

The monitor's color should be calibrated often because the color gamut can change over time due to age and environmental factors. A calibrated monitor helps ensure a closer resemblance to the final printed piece, although it still won't be exact. See color management for more information.