Xerox Fiery color server, User Manual

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1-2 Simple and Advanced Workflows
RGB, CMYK, and spot colors
Colors can be defined in several different color models, the most common being
RGB , CMYK , and the spot color matching system. Each model requires a different
color conversion at the Color Server. These different color conversion workflows
are as follows:
• RGB source profiles and color rendering dictionaries (CRDs) are used to map
RGB colors through a device-independent color space to a destination space, either
the full device gamut in a short-run printing workflow or CMYK simulation in a
color proofing workflow.
• CMYK colors are device-dependent. In a proofing scenario, colors specified in
prepress applications are adjusted so that the gamut of the printer simulates that
of the press. In a short-run printing workflow, specifying CMYK colors according
to the calibrated Color Server output eliminates the need for simulation
during printing.
• Spot colors, such as PANTONE, are special inks manufactured to run on an offset
printing press. Spot colors can be simulated using CMYK toners or process color
inks. Two basic workflows exist for printing spot colors to the Color Server:
Spot Color Matching On
uses color tables built in the Color Server to simulate the
spot color with its closest CMYK equivalent.
Spot Color Matching Off
instructs the Color Server to simulate the spot color using
CMYK equivalents defined by the spot color manufacturer. These are the same
CMYK values used by applications that include spot color libraries. This CMYK
combination is then printed with the CMYK Simulation setting you choose, such as
SWOP or DIC.
Desktop versus ColorWise color management
A desktop color management system uses ICC profiles to convert colors from one
device gamut to another (see
Appendix A ). The color data is converted when it is
passed from one application to another or when the job is sent to the printer; thus, the
processing occurs on
your computer, as opposed to the Color Server.