Working with color profiles

Precise, consistent color management requires accurate ICC-compliant profiles of all of your color devices. For example, without an accurate scanner profile, a perfectly scanned image may appear incorrect in another program, simply due to any difference between the scanner and the program displaying the image. This misleading representation may cause you to make unnecessary, time-wasting, and potentially damaging “corrections” to an already satisfactory image. With an accurate profile, a program importing the image can correct for any device differences and display a scan’s actual colors.

A color management system uses the following kinds of profiles:

Describe how the monitor is currently reproducing color. This is the first profile you should create because viewing color accurately on your monitor allows for critical color decisions in the design process. If what you see on your monitor is not representative of the actual colors in your document, you will not be able to maintain color consistency.

Describe what colors an input device is capable of capturing or scanning. If your digital camera offers a choice of profiles, Adobe recommends that you select Adobe RGB. Otherwise, use sRGB (which is the default for most cameras). Advanced users may also consider using different profiles for different light sources. For scanner profiles, some photographers create separate profiles for each type or brand of film scanned on a scanner.

Describe the color space of output devices like desktop printers or a printing press. The color management system uses output device profiles to properly map the colors in a document to the colors within the gamut of an output device’s color space. The output profile should also take into consideration specific printing conditions, such as the type of paper and ink. For example, glossy paper is capable of displaying a different range of colors than matte paper.

Most printer drivers come with built‑in color profiles. It’s a good idea to try these profiles before you invest in custom profiles.

(Not applicable to PDFs) Define the specific RGB or CMYK color space of a document. By assigning, or tagging, a document with a profile, the application provides a definition of actual color appearances in the document. For example, R=127, G=12, B=107 is just a set of numbers that different devices will display differently. But when tagged with the Adobe RGB color space, these numbers specify an actual color or wavelength of light—in this case, a specific color of purple.

When color management is on, Adobe applications automatically assign new documents a profile based on Working Space options in the Color Settings dialog box. Documents without assigned profiles are known as untagged and contain only raw color numbers. When working with untagged documents, Adobe applications use the current working space profile to display and edit colors.

About monitor calibration and characterization

Profiling software can both calibrate and characterize your monitor. Calibrating your monitor brings it into compliance with a predefined standard—for example, adjusting your monitor so that it displays color using the graphics arts standard white point color temperature of 5000° K (Kelvin). Characterizing your monitor simply creates a profile that describes how the monitor is currently reproducing color.

Monitor calibration involves adjusting the following video settings:

The overall level and range, respectively, of display intensity. These parameters work just as they do on a television. A monitor calibration utility helps you set an optimum brightness and contrast range for calibration.

The brightness of the midtone values. The values produced by a monitor from black to white are nonlinear—if you graph the values, they form a curve, not a straight line. Gamma defines the value of that curve halfway between black and white.

The substances that CRT monitors use to emit light. Different phosphors have different color characteristics.

The color and intensity of the brightest white the monitor can reproduce.

Calibrate and profile your monitor

When you calibrate your monitor, you are adjusting it so it conforms to a known specification. Once your monitor is calibrated, the profiling utility lets you save a color profile. The profile describes the color behavior of the monitor—what colors can or cannot be displayed on the monitor and how the numeric color values in an image must be converted so that colors are displayed accurately.

Most profiling software automatically assigns the new profile as the default monitor profile. For instructions on how to manually assign the monitor profile, refer to the Help system for your operating system.

Install a color profile

Color profiles are often installed when a device is added to your system. The accuracy of these profiles (often called generic profiles or canned profiles) varies from manufacturer to manufacturer. You can also obtain device profiles from your service provider, download profiles from the web, or create custom profiles using professional profiling equipment.

• In Windows, right-click a profile and select Install Profile. Alternatively, copy the profiles into the WINDOWS\system32\spool\drivers\color folder.
• In Mac OS, copy profiles into the /Library/ColorSync/Profiles folder or the /Users/[username]/Library/ColorSync/Profiles folder.

  After installing color profiles, be sure to restart Adobe applications.

Embed a color profile

You can embed a color profile in an object. Acrobat attaches the appropriate profile, as specified in the Convert Colors dialog box, to the selected objects in the PDF. For more information, see Color conversion and ink management (Acrobat Pro).

Convert colors to another profile (Acrobat Pro)

You convert colors in a PDF using the Convert Colors tool available in Print Production. For more information, see Color conversion and ink management (Acrobat Pro).

• About color working spaces