FUNDAMENTALS OF
COLOR
Light - Radiated when electrons in molecules move from a higher
energy level to a lower one. A photon is produced to maintain
conservation of energy and momentum.
If some of this radiated energy falls within the visible wavelength range
it is detected by the human eye. Visible light is a small part of the
electromagnetic spectrum, which includes X-rays, ultraviolet (UV),
microwaves, Infrared (IR), radar and radio waves.
Visible light lies in the 400 and 700 nm range of wavelengths. X-rays
and UV have shorter wavelengths and microwave, IR, radar and
radio waves have longer wavelengths than visible light. Some
mammals can perceive into the IR and UV range.
White light - Composed of many colors, essentially all of the visible
colors in the visible range with equal intensities of each
wavelength. Isaac Newton showed that white light could be split
into all colors of the rainbow by passing through a prism.
Visible light appears to be split up into three predominant bands of
light, red, green and blue. This results from how the human eye
perceives light in terms of red, green and blue.
Thus, these are called the primary colors of light. Balanced amounts
of R, G and B produce white light. Computer monitors and TV
screens use RGB to display color.
Additive Color Treory
White light is the sum of red, green and blue light. Black is the
absence of color. Used for transmissive colors, i.e. light shines
through an object. e. g. TV screen, Computer monitor,
transparencies.Secondary colors are produced from two color
overlap.
 Blue + Green = Cyan
 Red + Blue = Magenta
 Green + Red = Yellow
Combining in unequal proportions yields new colors. Essentially all
perceivable colors can be represented by different amounts of
RGB. RGB is usually the native color model used by computers
and is also used on most desktop scanners.
Subtractive Color Theory
Secondary colors are used as subtractive primaries, Cyan, Magenta and Yellow.
Used when light is reflected from an object such as printed page or
photograph. Pigments are examples of subtractive colors which reflect
some wavelengths and absorb or subtract others. Cyan pigment absorbs
Red and reflects Green and Blue, i.e. appears cyan. Magenta pigment
absorbs Green and reflects red and blue, i.e. appears magenta. Yellow
pigment absorbs blue and reflects red and green, i.e. appears yellow. When
subtractive primaries are overprinted you get Red, Green and Blue (RGB).
The subtractive primaries (CMY) can be thought of as the complements of
R, G and B respectively.

Cyan + Yellow = Green

Cyan + Magenta = Blue

Magenta + Yellow = Red

Cyan + Magenta + Yellow = Black
Raster(True) Proofing
If the digital printing methods can be modeled and raster structure of
the future of the printed impression, then talk about raster proofing
True-Proof). In this case, the quality of proofs, and also reproduces
the structure of a raster image, the maximum is close to the quality
of software distribution impression. Information about the structure
of the halftone dots is a printmaker, inter alia, for the early detection
of deviations of the size of halftone dots and the associated color
changes or deviations in matching colors. If necessary, you can
specifically interfere with the gradation curve of the process.
Hard proof
In the printing industry in the
manufacture of high-quality
reproductions of proofing is to obtain
images within the gamut of real
synthesis of the printed (in color
reproduction) and indicates the
suitability of the content of the file for
output. To do this all the more widely
used standard printing systems, such
as ink-jet printers (Figure 75, four-lane
A4) or dye-sublimation printer (Fig. 71,
2-page format) in combination with
high-performance color management
system.
This type of proofing guide the printer responsible for circulation.
Effects due to the raster
structure, such as
gloss, contrast and
range of variation of
tones, or rosette moire
effects can be
identified prior to the
printing process and if
necessary, discussed
with the customer.
To produce a true colorscanning, ensuring
identity with print run
impression, some
manufacturers offered
a number of special
systems using real
paint multicolor
printing synthesis
(CMYK). Proofs are
made with the use of
color films and thermal
transfer dyes for
special media or on the
lottery paper.
Proof Print
Proofs performed on
Press-Proof, called
proofrun . Short runs of
50 to 100 copies can be
produced more costeffectively than with
other color proof
processes. But for an
individual (sole) color
test this method
economically
unjustified.