Subtractive Colors - Konica Minolta Magicolor 7300 Reference Manual

Subtractive Colors

If we direct white light
onto an object, such as a
red apple, the white light
seems to be modified in
such a way that only the
red part is reflected to our
eyes. This means that
the apple must have absorbed the green and blue portions of the white light.
This is why we say that the apple looks red. Further analysis shows that the
object may be considered as having certain pigments responsible for the
absorption. These pigments are cyan, magenta, and yellow (CMY) in a
particular ratio. These are called the primary subtractive colors (subtracting or
absorbing portions of red, green, and blue from white light).
The relationship between additive colors and subtractive colors may be
explained by using the result obtained with the flashlight experiment on the
previous page. Notice that for light sources (= light-emitting objects) the
following applies:
!
Red light mixed with green
light produces yellow light
!
Green light mixed with blue
light produces cyan light
!
Blue light mixed with red light
produces magenta light
The opposite colors on this
"wheel" are complementary,
which means that for
light-reflecting objects, the
following applies:
!
Red light is absorbed by
cyan pigments
!
Green light is absorbed by
magenta pigments
!
Blue light is absorbed by yellow pigments
In the case of our red apple, the pigments responsible for the absorption must
be magenta (absorbing the green light) and yellow (absorbing the blue light),
while the red light is not absorbed and is reflected.
" #
Mixing equal amounts of cyan, magenta, and yellow pigments
produce black pigment (because all the red, green, and blue portions
of white light are absorbed). Black, therefore, is the absence of color.
Color Management
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