IBM 1800409-001A - Manual (Page 246)

Color Management
A major concern in the color publishing industry today is keeping
color consistent across devices with different color models. For
example, when you scan a color photograph, the scanner sends the
image data to the computer in an RGB (Red-Blue-Green) format.
The computer then converts the data into another RGB format to
display it on the monitor. When the image data is sent to the printer,
it is converted into CYMK (Cyan-Magenta-Yellow-blacK) format
by the printer driver or application. Because of these conversions,
a color output device (like your printer) may produce colors
dramatically different from those seen on the computer screen, or
in the original image.
To keep colors more consistent, you can use color management.
Color management involves two processes: calibration and color
matching.
Device Calibration
Calibration ensures that the hardware of a targeted device produces
consistent color every time.
Color Matching
Even if you calibrate your color-generating devices, these devices
still speak different color languages unless you have a color
management system to translate between them. Color matching
uses software to describe colors for different devices in a common
language to make sure that color is produced in the same shade on
all devices.
Chapter 7
7 - 1 2 O p t i m i z i n g C o l o r O u t p u t