Specifying working spaces

In a color-managed workflow, each color mode must have a working space profile associated with it. (See About working spaces.) Photoshop ships with a standard set of color profiles that have been recommended and tested by Adobe Systems for most color management workflows. By default, only these profiles appear in the working space menus.
To display additional color profiles that you have customized or installed on your system, select Advanced Mode in the Color Settings dialog box. To appear in a working space menu, a color profile must be bidirectional, that is, contain specifications for translating both into and out of color spaces. You can also create a custom RGB, CMYK, Grayscale, or Spot working space profile to describe the color space of a particular output or display device. (See Creating custom RGB profiles, Creating custom CMYK profiles, and Creating custom grayscale and spot-color profiles.)
For information about a specified RGB or CMYK working space profile, see the Description area of the Color Settings dialog box. (See Setting up color management.) The following information can help you specify an appropriate Gray or Spot working space:
• For images that will be printed, you can specify a Gray or Spot working space profile that is based on the characteristics of a particular dot gain. Dot gain occurs when a printer's halftone dots change as the ink spreads and is absorbed by paper. Photoshop calculates dot gain as the amount by which the expected dot increases or decreases. For example, a 50% halftone screen may produce an actual density of 60% on the printed page, exhibiting a dot gain of 10%. The Dot Gain 10% option represents the color space that reflects the grayscale characteristics of this particular dot gain.
Proof (no dot gain), and printed image (with dot gain)
• For images that will be used online or in video, you can also specify a Gray working space profile that is based on the characteristics of particular gamma. A monitor's gamma setting determines the brightness of midtones displayed by the monitor. Gray Gamma 1.8 matches the default grayscale display of Mac OS computers and is also the default grayscale space for Photoshop 4.0 and earlier. Gray Gamma 2.2 matches the default grayscale display of Windows computers.