The three key points are: 1. Light is a form of radiant energy that consists of photons behaving in a uniform wave pattern. Visible light is a small portion of the electromagnetic spectrum perceivable by the human eye between 400-700 nm wavelengths. 2. Color is perceived when light strikes an object and is reflected to the eye. The wavelengths reflected or absorbed by the object determine the color perceived. Pigments selectively reflect wavelengths to produce color. 3. In light theory, the primary colors are red, blue, and green, while in pigment theory they are red, yellow, and blue. Additive color mixing combines light wavelengths, while subtractive mixing combines pigments. Both produce different

1. Visual Imagination

2. It is now an accepted fact that color is truly
in the eye of the beholder. "This is due to
the fact that, as sensed by man, color is a
sensation and not a substance."
Joseph Friedman - History of Color Photography

3. In 1704 Isaac Newton first passed a beam of white
light through a prism, and saw it divide into multiple
and varied color bands. He defined it as the
spectrum.

4. Sunlight
Prism
A
Shade
Inversely, he determined that, combining all color
bands together produces pure white light or sunlight.
Newton thought that light was a stream of tiny
particles.
In 1801, Thomas Young conducted an experiment
that provided evidence that visible light has wave-like
properties.

5. Light waves are reflected or absorbed by surfaces of
objects around us.
The reflective characteristics of a surface allow us to
interpret certain light-wave qualities as particular
colors.
Hence the theory: color is a property of light.

6. To understand color it is, therefore, necessary to
have some understanding of light.

7. What is
Light?
Light is a form of radiant energy that consists of
separate bits of energy particles called photons
that behave in a uniform wave pattern.

8. Light is just the small, portion of the larger
electromagnetic continuum (spectrum)
that is visible by the naked eye.
ELECTROMAGNETIC SPECTRUM
10-14 meters
106 meters
Cosmic Gamma X-rays UV
Rays
Rays
Light
InfraRed
Microwaves
TV
VISIBLE SPECTRUM
400
500
600
Wavelength (nm)
700
Radio

9. The region of visible light falls between the
ultraviolet and infrared regions.
ELECTROMAGNETIC SPECTRUM
10-14 meters
106 meters
Cosmic Gamma X-rays UV
Rays
Rays
Light
InfraRed
Microwaves
TV
VISIBLE SPECTRUM
400
500
600
Wavelength (nm)
700
Radio

10. Light waves are measured in nanometers (nm) which are
equal to 1 billionth of a meter (1 nm = 10-6 meter).
.
ELECTROMAGNETIC SPECTRUM
10-14 meters
106 meters
Cosmic Gamma X-rays UV
Rays
Rays
Light
InfraRed
Microwaves
TV
Radio
VISIBLE SPECTRUM
400
500
600
700
Wavelength (nm)
Light, then, is electromagnetic energy whose wave-length
is measured between 400 nm and 700 nm.

11. The size of the wave (wavelength and amplitude)
determines the color of light

12. Although some colors can be created by a
single, pure wavelength, most colors are the
result of a mixture of wavelengths.
A French organization, the Commission
International de L'Eclairage (CIE), developed
a method for systematically measuring color
in relation to the wavelengths they contain.
This system became known as the CIE color
model (or system).

13. The model was originally developed based on the
tristimulus theory of color perception. The theory is based
on the fact that our eyes contain three different types of
color receptors called cones. These three receptors
respond differently to different wavelengths of visible light.
This differential response of
the three cones is measured
in three variables X, Y, and Z I
n the CIE color model.
This gives a 3-D model which
is then projected onto one
plane to give a 2-D graphic.
X Y and Z are mapped to X and Y coordinates

14. The spectral energy locus, shows the
distribution of light wavelengths in terms of
nanoseconds, clearly separating the visible
spectrum into 3 principal ranges.
At the extreme ends
of these ranges are
the three principal
colors or hues of
light.
RED
BLUE
GREEN

16. What is Color?
COLOR is a phenomenon of perception not an
objective component or characteristic of a
substance. Color is an aspect of vision; it is a
psychophysical response consisting of the physical
reaction of the eye and the automatic interpretive
response of the brain to wavelength characteristics
of light above a certain level of brightness.

17. Three factors must be present for color to be
perceived: light, the object light strikes, and
the observer who perceives this event.

18. When we talk about the color of an object, we usually
refer to the wavelength that object reflects when struck
by natural light.
• Wavelengths of light reflected
or absorbed by object
determine the color we
perceive an object to be.
• Only reflected wavelengths
reach our eye and are seen as
color
• chemicals that are capable of
selectively reflecting one or
more frequencies of white light
are known as a pigments.

20. We will return to light theory a little later on,
but for now, our concern will be with the mixture
of pigments rather than the mixture of various light
frequencies.

21. What is
Pigment ?
Pigment is the surface property of of a material
that allows it to absorb and reflect specific
light frequencies.
Pigments are also natural or synthetic agents that
constitute the color in paint.

22. The mixing of pigment colors yields additional color
combinations similar to that observed in light .
Pigment color mixing is termed subtractive color
mixing. It is so termed because the resulting colors
are somewhat duller than the primaries, revealing
less reflective properties, or less color “brightness.”

23. Pigment color theory is based on the three primary
colors of pigment: red blue and yellow. These
three colors are pigment equivalents of the
spectral red, blue and yellow. They are so termed
primary because they
cannot be produced by
the mixture of any other
colors.

24. Although color theories existed since Aristotle’s
time, the 18th century generated a great deal of
interest in color relative to both light and pigment.
The renowned philosopher,
poet and scientist Wolfgang
von Goethe constructed the
first practical color wheel
which was comprised of six
spectral colors evenly
distributed around a circle.
Goethe color wheel

25. In the same century, Herbert Ives expanded on
Goethe’s color wheel and devised a model which
showed that a full
range of spectral
hues can be obtained
through the admixtures
of the three primary
hues and the secondaries
they form.
Ives color wheel

26. Albert H. Munsell, a late 19th and early 20th century painter,
developed a system of color notation that is used up to this day
as one of the color standards used by the US National Bureau of
Standards. Munsell’s 3-D color “tree”, is one of the
most
thorough
analyses of color
to this date. It is,
however, based on
the 12 hue color
wheel developed
by Ives.

27. The three primary colors in pigment are:
RED, BLUE AND YELLOW

28. When the three primaries are combined or mixed
they form the three secondaries:
GREEN, ORANGE AND VIOLET

29. When primaries are mixed with adjacent secondaries,
intermediates are formed.

30. When secondary colors are mixed they form tertiaries.
Orange/Green
Orange/Violet
Green/Violet
Tertiary colors do not exist on the
color wheel.

31. When a primary is mixed with a non- adjacent
secondary it forms a neutral.
Neutral colors do not exist on the color wheel.
Neutral colors are comprised of various quantities of
all three primaries

32. Secondaries opposite the primaries on the Ives
color wheel are called complements.
Any two colors opposite each other on the color
wheel are also called complements.

33. Complementary colors intensify the effect of each
other. This effect is called simultaneous contrast.

34. When a color is placed against a gray
background, the background appears as a dull
version of the color’s complement.

35. Remember, the only pure colors are spectral
colors (those present in light) all pigment colors
are, in some way,effected by the surface they
are observed from.

36. THE CHARACTERISTICS OF COLOR
Non-colors that affect color quality.
IN THEORY
WHITE: In pigment – the absence of color
BLACK: In pigment – the sum of all color
BLACK
GRAY: Any mixture of gray and white

37. HUE – A pure color, containing no other color, black,
white or gray.
TINT – A hue with white added
SHADE - A hue with black added.
TONE - A hue with black and white gray added

38. VALUE – The relative lightness or darkness of a color.
Values can be altered by adding white or
black to a color.
CHROMATIC VALUE SCALE

39. Value:
Light and dark values are low in intensity. Middle
values are highest in intensity.

40. SATURATION – The density of same color pigment
properties.
High medium and low saturation
High saturation
Low saturation

41. CHROMA - The degree of purity in a color.
Higher in Chroma Lower in Chroma
High Chroma
Low Chroma

42. INTENSITY – The relative brightness or brilliance of
a color, resulting from the degree of saturation or
chroma.

43. Light Color Theory:
A slight review:
Observing light, as observing pigment seems to
hardly require a theory of any kind. It is when we
attempt to use light and pigment, in some creative or
constructive way, that we look for an explanation
regarding the nature and behavior of these
phenomena.
In pigment, a practical model for mixing colors was
created by the color wheel. Is this possible in light
theory?

44. Light is a form of radiant energy that is just a small
part of the larger electromagnetic continuum that is
perceivable by the naked eye. Visible light falls
between the infrared and ultraviolet regions.
400
450
500
550
600
650
700
Wavelength (nm.)
Problem
Redness at the shortest and longest wavelengths

45. Fortunately, through experiments performed to observe and measure what people see, an explanation does
exist. Human color sensitivity was mapped into a perceptually uniform color space known as CIELAB. (We
have seen this previously.) Since the human
eye forms a natural continuity
in color vision, and is not
Interrupted in any way by
the discrepancy of if IR and
UV frequencies, a color band
or “wheel” can be formed to
create a practical relationship
between the hues.

46. By placing the spectral colors in a circle, we can
observe a curious relationship. The frequency
between a certain green (500 nm) and red (700
nm.) is a yellow (600 nm. - called amber)
Similarly, the frequency
between green (500 nm.)
and blue (470 nm.) was
Identified as cyan (485 nm.)
Since the visible spectrum
extends from ultra-violet to
Infra red, that “purple” range
of the spectrum is combined
To form “non spectral” hues.
YELLOW
CHARTREUSE
ORANGE
580
550
GREEN
500
620
700
Spectral
Hues
RED
Nonspectral
Hues
485
CYAN
400
470
BLUE
PURPLE

47. Light Color Theory
As previously mentioned, in light, there are also
three primary colors: red, blue and green. They
Are termed primary because their admixture, in
different values and intensities, will yield the
remaining colors in the visible spectrum.

48. Additionally, when the primary colors are individually
introduced (from separate light sources), and are
superimposed on each other, on a neutral surface
they produce white light.
Mixing colors in this
way is termed additive
color mixing.

49. Additive color mixing is so termed, because
new colors are formed as new light frequencies
are added to each other.
For example: when a red color
frequency is superimposed on a
green one, a yellow (Amber)
frequency emerges.
The secondary colors
Of light are: amber
magenta and cyan.

50. There is also subtractive color mixing in light.
This is achieved by superimposing color filters
on each other within a single source of light. In
the theatre these filters are called gels.
When superimposed, filters
block each other’s frequencies
until all light is absent.
To remove all traces of light it is best to use secondary color filters
Namely : amber.

51. The Effect of Color Filters on Color and
Light Transmission

52. Introducing individual color frequencies to colored surfaces
Also results in subtractive color mixing.

53. A clown under natural lighting (all light frequencies).

54. Green
Cyan
Green – allows mostly green and
amber wavelengths.
Cyan - allows no reds
Amber – allows no blues or violets
Red – allows nothing but red
Amber
Red

55. Much of the terminology used in Pigment Color
Theory does not apply to Light Color Theory.
Terms such as Value, Saturation, Chroma are
typically not Employed.

56. Here are some terms to remember:
INTENSITY - the amount of light being transmitted
HUE - Color
WHITE (in light) – The sum of all color frequencies.
BLACK (in light) – The absence of light.
WARM and COOL color ranges also exist in light
But are slightly different from their pigment
counterparts.