Digital Prints

The subtractive primary colors are Cyan, Magenta, and Yellow. The secondaries are Red,
Green, and Blue (see Figure 4.3).
The additive color system, which applies to light coming from a computer monitor or
stage lighting, is different in that if you add colors, you ultimately end up with white,
not black. The additive primaries are Red, Green, and Blue. The secondaries are Cyan,
Magenta, and Yellow.
Here’s how color is created on computer monitors. Traditional cathode-ray-tube (CRT) monitors
have “guns” that shoot electron beams toward the inside of the screen where they strike
a phosphor coating. When a beam hits a red phosphor, it gets excited and emits light—light
of a wavelength perceived as red. The same thing happens with the green and blue phosphors.
As the voltage of a gun changes, so does the intensity of the light. (Flat-panel, LCD
monitors work differently by using filters to either block the light or allow it to pass. There
are no electron guns; instead, tiny transistor switches—one each for red, green, and blue—
sit in front of each screen spot and control the light through polarization.)
Corresponding to the binary data in the digital file, each pixel on a monitor screen is made
up of combinations of red, green, and blue in varying intensities (256 levels in 8-bit mode).
All the other secondary colors come from differing combinations and values of the three
primary colors. As the intensities (brightness) of the individual colored pixels increase,
they get lighter.
Light Sources and Color
Light sources also have their own “colors” associated with them. That is, you can draw a
spectral curve of the light source with each wavelength charted (see Figure 4.4).
The type of light source will affect anything displayed under it, and this is where the
dreaded word metamerism comes into play.
Metamerism (pronounced me-TAM-er-ism) is greatly misunderstood as only being a “problem”
with certain types of inks, when in fact, it is a normal phenomenon relating to how
we see color. I’ll discuss the ink-problem aspect of it in Chapter 7, but for now I define
Chapter 4 ■ Understanding and Managing Color 117
Figure 4.3 The subtractive primaries
(left) and the additive primaries (right).
Notice how the overlaps (secondary
colors) become the primary colors of the
other system (and at the same time the
complement of the remaining primary).