We consider every topic in this book to be important, but color management is one of those subjects that can quickly make anyone feel stupid. If you're under the delusion that you can use Adobe Photoshop without using color management, this chapter is a must-read. Without understanding how Photoshop handles color behind the scenes, there's no way to get great color (or black-and-white) images out of this program.
Although the color management system in Photoshop uses mathematics that approach rocket science, using the tools that control the system is fairly simple. You just need to understand a few key concepts, learn where the buttons are, and use common sense in deciding when to push them.
In the last chapter, we broke the sad news that RGB and CMYK are very ambiguous ways of specifying color, since the actual color you get will vary from device to device. In this chapter, we'll look at the features Photoshop offers to make what you see on the screen at least resemble, if not actually match, what you get in your printed output.
Writing just a chapter about color management doesn't do justice to the subject. If you read this chapter and find that you need more detailed information, pick up the book Real World Color Management (Peachpit Press) by color management guru Bruce Fraser, along with Chris Murphy and Fred Bunting.
What Is Color Management Anyway?
Color management can be an intimidating subject for photographers. With such a dry name, color management is often perceived as a technical chore to be avoided whenever possible. But hardware and software vendors have devoted a great deal of time and resources to working color management into every nook and cranny of digital photography, so it must be important, right? Right: Color management exists because it solves a problem. But what problem does it solve?
You may already know that colors don't look the same from camera to display to printer for all kinds of reasons, from simple production variations to the fact that some devices (like displays) use additive color and others (like printers) use subtractive color, a fundamentally incompatible conflict. This is the problem color management tries to solve, and it does so by creating a common foundation that color hardware and software can use to make color more consistent.
Ultimately, color management is about reconciling color differences. You could try doing this manually by fiddling with your monitor and printer controls, but it would mean that your files would display and print properly only with the specific hardware and software you currently have in front of you. If you upgrade any of your equipment or send the file to someone else, the file won't look the same because it won't have been tweaked for the new equipment.
A color management system is a much better solution because it uses standardized profiles that describe how your hardware and software reproduce color. When you want to display or print image colors properly on a system with different hardware or software, as long as you have profiles that describe the hardware and software being used, the color management system can make the adjustments necessary to reproduce the image colors consistently. If you think of a display and a printer as using different color "languages," you can think of a color management system as a sort of translation layer between your image and the system it's on, and profiles as language phrase books used to translate colors from one device to another.
Yes, color management can be a challenge to understand, but the effort is well worth it. Even understanding just the basic ideas of color management can give you skills that save you time and frustration when trying to get colors to reproduce consistently in many environments.
Color Management Is About Answering Simple Questions
To simplify the way you think of color management, it helps to remember that ultimately, what you're trying to do is answer a few questions about the image in front of you:
- How is this image supposed to look?
- Where did this image come from? (Under what viewing conditions was this image edited?)
- Where is this image going? (What are the editing or output conditions where the image is going next? How should the colors be preserved under those conditions?)
These questions may seem random now, but you'll soon see that if you keep these questions in mind when you're trying to decide which button to push in a cryptic color management dialog, you'll find it much easier to think through your answer. We will come back to them.
Color Management Is About Relationships
Those new to color management sometimes become fixated on the individual pieces of the system, such as a monitor or a printer. But focusing on an individual piece misses the point. Because the goal is to keep colors consistent among different parts of a workflow, what you really want to pay attention to are the relationships between those parts. The questions we just posed help you find out about relationships within a workflow.
Profiles are a way of recording and communicating those relationships. For example, when you calibrate a monitor to specific viewing conditions, such as a color temperature of 6500 Kelvins, or K, at gamma 2.2, a monitor typically can't achieve that standard exactly. The monitor profile fills the gap, telling the system how much to alter the display signal so that the image on the monitor does meet the standard. This means that the profile has recorded the relationship (the difference) between the monitor's performance and the desired standard and has communicated it to the system. The system can then make up (compensate for) the difference. As a result, you see a consistent representation of the colors in the image.