Producing Consistent; Why Colors Sometimes Don't Match; About Color Management - Adobe PHOTOSHOP 6.0 Manual

Chapter 4: Producing Consistent Color
(Photoshop)
hen your document must meet
W
color standards set by clients and
designers, viewing and editing color
consistently becomes critical, all the way from
scanning source images to creating final output.
A color management system reconciles color
differences among devices so that you can be
reasonably certain of the colors your system
ultimately produces.
Why colors sometimes
don't match
No device in a publishing system is capable of
reproducing the full range of colors viewable to the
human eye. Each device operates within a specific
color space, which can produce a certain range,
or gamut, of colors.
The RGB (red, green, blue) and CMYK
(cyan, magenta, yellow, black) color modes
represent two main categories of color spaces.
The gamuts of the RGB and CMYK spaces are very
different; while the RGB gamut is generally larger
(that is, capable of representing more colors) than
CMYK, some CMYK colors still fall outside the
RGB gamut. (See "Color gamuts (Photoshop)" on
page 114 for an illustration.) In addition, different
devices produce slightly different gamuts within
the same color mode. For example, a variety of
RGB spaces can exist among scanners and
monitors, and a variety of CMYK spaces can exist
among printing presses.
Because of these varying color spaces, colors can
shift in appearance as you transfer documents
between different devices. Color variations can
result from different image sources (scanners and
software produce art using different color spaces),
differences in the way software applications define
color, differences in print media (newsprint paper
reproduces a smaller gamut than magazine-
quality paper), and other natural variations,
such as manufacturing differences in monitors or
monitor age.

About color management

Because color-matching problems result from
various devices and software using different color
spaces, one solution is to have a system that inter-
prets and translates color accurately between
devices. A color management system (CMS)
compares the color space in which a color was
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