Xante Colour ScreenWriter, User Manual

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_______________________________________ Color Printing 8-5
Color Printing Concepts and
Variables
To understand how colors are transformed from one color space to
another, it is important to look at some basic color concepts and
printing variables that affect color printer output.
Color Theory
Color display is founded on traditional theories of color and light
principles. The color of an object is dependent upon the wavelengths
of light reflected by the object. A white object reflects the
wavelengths of all colors in the visible spectrum and a black object
reflects none of these wavelengths. Because the cones in the retina of
the human eye are more sensitive to either red, blue, or green, these
colors are the basis on which we perceive and describe color. All
colors that are visible to the unaided human eye can be described as
combinations of these three primary colors. RGB (additive color
theory) and CMYK (subtractive color theory) are two methods
commonly used to define the combinations of the three primary
colors required to produce all other colors.
Additive Theory
Since a color monitor produces light, it begins with black (no light)
and adds specific proportions of red, green, and blue light to create
other colors. Adding together equal quantities of all colors creates
white. RGB, or the additive color theory, defines all colors as a
specific combination of red, green, and blue wavelengths.
Red
Magenta
Blue
Cyan
Green
Yellow
(Primary)
(Primary)
(Primary)
(Secondary) (Secondary)
(Secondary)
Red
Cyan
Yellow Magenta
Green Blue
(Secondary)
(Secondary)
(Secondary)
(Primary)
(Primary)
(Primary)
Fig. 8.2 Additive RGB and Subtractive CMYK Colors