How-To Articles

Color Basics Part 6 – Color Gamuts

Color Basics Part 6 – Color Gamuts

Color gamut is another word for range of colors. The color gamut of a device is the maximum range of colors that the device can reproduce. This is based on the highest achievable capabilities of the colorants used by that device, colorants such as red green and blue phosphors of a typical computer monitor, or cyan, magenta and yellow inks of a printing press.

Imagine the color gamut of the human eye and brain. As described earlier, the 3-D color space can occupy approx. 50 million of the colors perceptible by the human eye. Now factor in the physics of a computer monitor. The phosphors in the monitor make it possible to view approximately 15 million different colors. Pretty good until you calculate that 15 million is only 30% of the colors perceptible by the human eye. Let’s add more physics. The ink in your printing company’s press can reproduce a few million colors with process inks. Great! Until we realize that only about 50% of the colors on the monitor can be reproduced on a printing press, or about 15% of the colors picked up by the human eye! And of course, there are colors that the monitor can recognize that cannot be printed, as well as colors that can be printed that cannot be shown on a monitor. (It’s any wonder we get high quality looking pieces at the end.)

There is one more thing to factor in; Proofs. The color gamut of desktop printers, high quality ink jet printers, film output devices, film color proofs such as MatchPrint, are all way different from each other. You are hopefully beginning to see the challenge that many printers and designers are faced with to get the results that everyone is happy with.

To illustrate, consider what it would be like if you limited yourself to three crayons in which to create a picture; say blue, yellow, and red crayon. It’s easy to understand that your range of colors would be limited. Using the blue and yellow crayons, you could make a nice green. You could make it lighter or darker, more blue or more yellow, but there would be many greens that you could not make without changing to a different crayon. Now consider what would happen if you passed your picture, made with your three crayons, onto someone else for reproduction, and they had three different crayons to work with. Just as in the real world of image reproduction, it is likely that the reproduced color would not match the original, nor be predictable.

The concept of color gamuts and how we adjust then as we move color images across a wide variety of electronic devices is key to success in today’s color workflow. This will be discussed in a future part in this series.