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Chapter 11 ∣ Color
Copyright Goodheart-Willcox Co., Inc.
The various color systems and color models
describe colors through numerical or coordinate
means. The numerical values or coordinates
allow the colors to be defined within the system’s
parameters. These parameters define the system’s
color space. The term space is used because color
data occur in three dimensions. The color space
defines the limits by which the color model can be
used. The full range of colors that can be defined
by a color model is called a color gamut. To better
define color space, many color models are triaxial.
A triaxial system involves three axes (vertical, side-
to-side, front-to-back). This section addresses the
various color spaces in common use today.
Color organization begins with two small groups:
pure chromatic colors and achromatic colors (white,
grays, and black). All other colors exist within these
two extremes.
The Color Wheels
A color wheel consists of a range of colors in
the form of a circle and is useful for demonstrating
the relationships among colors. The colors can be
described as primary, secondary, or tertiary.
Painted Color Wheel
Coming after many years of discussion, revision,
and scientific study dating back to Sir Isaac Newton
in 1672, the color wheel has long been based on the
color spectrum composed of the seven colors of the
rainbow: red, orange, yellow, green, blue, indigo, and
violet (ROYGBIV). For centuries, artists have utilized
this color wheel as defined by the use of pigments
with the main colors, or primary colors, of red, yellow,
and blue. Secondary colors are orange, green, and
violet. Other colors on the wheel, known as tertiary,
or intermediate, colors are yellow-green, blue-green,
blue-violet, red-violet, red-orange, and yellow-orange.
See Figure 11-6.
Primary colors are defined as colors, that when
combined, create all other colors; and a color, in its
purest form, that cannot be created by any combination
of colors. Secondary colors are created by mixing equal
amounts of two primary colors. For example, orange
is made by mixing yellow and red pigments. Green
is made by mixing yellow and blue. Violet is made
by mixing blue and red. The secondary colors are
positioned between the primaries on the color wheel.
Tertiary colors are made by mixing a primary color
with a secondary color. These colors are named after
the two colors used to make them, with the primary
color listed first. For example, yellow-orange is created
by mixing the primary color yellow with the secondary
color orange. Although not the true color wheel, this
works for fine artists and for mixing pigments.
True Color Wheel
Color as we see it is based on science and the
way our eyes function. The red, green, and blue cones
in our eyes allow us to see in color. This additive color
system of light is based on the true primary colors: red,
green, and blue. See Figure 11-7. As creatives work 7 7
almost exclusively within the digital environment using
computers and digital cameras, it is critical to embrace
the additive color wheel.
Color Triads
Any three colors that are an equal distance
apart on the color wheel compose a color triad.
The colors in a triad often go well together, so color
triads are important design tools. The primary,
secondary, and tertiary colors on the color wheel
all form triads, Figure 11-8. Placing almost any
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Figure 11-6. This color wheel presents the primary,
secondary, and tertiary colors of the color wheel as
determined by the use of pigments.
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