1. Understanding Color:
An Introduction for Designers
An Introduction for Designers
Chapter 2: A Little Light on the Subject

2. Part 1

3. Light

4. Only light generates color.

5. Light is visible energy that is emitted by a
light source.

6. A light source can be:

7. the sun...

8. a luminous panel...

9. a neon sign...

10. a light bulb...

11. or a monitor screen.

12. The eye is uniquely
adapted to receive light.

13. The retina of the eye receives a stimulus - the
energy signal - and transmits it to the brain,
where it is identified as color.

14. Light sources emit this visible energy in pulses,
or waves.

15. All light travels at the same speed, but waves of
light energy are emitted at different distances
apart or frequencies.

16. The distance between the peaks of these energy
emissions is called wavelength. Wavelengths of
light are measured in nanometers (nm).

17. The human eye is able to sense wavelengths of light
ranging from about 380 nm to about 720 nm.

18. Individual wavelengths are sensed as discrete colors, or
hues.

19. Red is the longest visible
wavelength at 720 nm.
Violet is the shortest visible
wavelength at 380 nm.

20. The wavelength of visible
light goes in order from
longest to shortest:
RED
ORANGE
YELLOW
GREEN
BLUE
INDIGO
VIOLET

21. “ROYGBIV” is an acronym for these
wavelengths, which are the colors of the
visible spectrum.

22. “ROYGBIV” is an acronym for these
wavelengths, which are the colors of the
visible spectrum.

23. Here is an easy way to remember the
order:

24. Different types of light sources emit the various wavelengths
(colors) at different levels of energy. One light may give off a
particular wavelength at such a low level of energy that it is
barely visible...

25. ...while another emits it so strongly that it is
seen as a brilliant color.

26. Although the color is the same, the intensity of the
color experience is very different.

27. The human eye is most sensitive to light in the middle range of
the visible spectrum and sees these colors, the yellow-green
range, most easily.

28. Yellow-green light
can be sensed at a
lower level of energy
than other colors.

29. There is visible light and color beyond the range of human
vision.

30. Some animals and insects can
sense colors that are beyond the
range of human vision.

31. For instance, jumping spiders and
bees can sense ultraviolet light.

32. Colors on the edges of human vision can also be sensed with
special optical equipment.

33. For instance,
there are special
filters and lenses
that you can
attach to a
camera to take
photos using
only infrared
light.

34. Additive Color:
Mixing Light
Mixing Light

35. Sunlight is sensed as
white, or colorless,
but it is actually
made up of a
mixture of colors
(wavelengths) that
are emitted in a
continuous band.
Individual colors can
be seen when
sunlight is passed
through a prism.

36. The glass of the
prism bends, or
refracts, each
wavelength at a
slightly different
angle so that each
color emerges as a
separate beam.

37. Under the right atmospheric conditions water droplets
will form natural prisms, and the compoenent colors of
sunlight can be seen as a rainbow.

39. Other
light
sources,
like light
bulbs, emit
light
perceived
as white.

40. But light sources do not have to emit all of the visible
wavelengths for white light to result.

41. White light is produced as long as a source
emits the red, green, and blue wavelengths in
roughly equal proportions.

42. Red, green, and blue
are the primary colors of light.

43. Mixing two of the primary colors of light
produces a new color.

44. Cyan, magenta, and yellow are the
secondary colors of light.

46. Wavelengths can be
combined in unequal
proportions to create
additional colors.

47. Two parts green light and one part red
at equal levels of energy provide yellow-
green.

48. Two parts red light and one part green at
equal levels of energy provide orange.

49. All hues, including violets and browns that are not
found as wavelengths in the visible spectrum, can be
produced in light by mixing the light primaries in
different proportions.

50. White or colored light seen as a result of a
combination of wavelengths is called an
additive mixture or additive color.

51. Lamps

52. Lamps are the principle man-made light sources.
“Lamp” is the correct term for a light bulb.

53. The fixture that holds the lamp is a luminaire.

54. A general light source is a lamp that
produces light that is white.

55. General light sources provide ambient light,
which is general area lighting.

56. A lamp that is missing one or more of the
primary colors gives off colored light.

57. It is NOT a general light source.

58. The lamps in neon signs are one example of a light
source emitting a narrow range of wavelengths

59. General light sources each produce wavelengths in a
characteristic pattern called a spectral distribution
curve or spectral reflectance curve.

60. The spectral distribution curve shows which wavelengths are
actually present and the strength of each wavelength relative to
the others for that particular type of lamp.

61. Spectral distribution determines (and describes) the color quality
of a light source.
Warm Neutral Cool

62. We think of natural and artificial light as two different
entities, but ALL light is visible energy.

63. Light sources
can be
• spectral distributio
differentiated
from other • apparent whitenes
each other in
two ways:

64. Daylight is the standard of whiteness for man-made light
sources, and because response to sunlight is part of our
genetic makeup, it also helps to determine whether light
from a given source will be sensed as more or less natural.

65. About 40% of man-made interior lighting is used for
domestic purposes.

66. The balance is used to illuminate public and commercial spaces.

67. Incandescent lamps, like the sun, produce light by burning.

68. The light they emit is a small byproduct of heat - only about 5%
of the energy used by an incandescent lamp results in light.

69. Candlelight, firelight, and incandescent lamplight are
sensed as comforting because they emit light in the
same way the sun does.

70. The apparent whiteness of an incandescent lamp
depends on the temperature at which it burns, called
its color temperature.

71. Color temperature
in lamps is
measured in
degrees Kelvin
(K).

72. A typical incandescent lamp burns at a relatively
low temperature, around 2600 - 3000 K.

73. Lamps that burn hotter emit bluer light; very
white light is hottest of all.

74. A halogen lamp is a type of incandescent lamp
with a gas inside the glass envelope that causes it
to burn at a high temperature resulting in a bluer
white.

75. The color temperature of a lamp is used as a measure of
whiteness for the color of light produced by the lamp.
It does not help to predict how a light source will render the colors
of objects.

76. As a designer, you will need to use mockups in field conditions
to make sure that the lamps you use deliver the right quantity
and quality of light for each situation.

77. Fluorescent lamps
produce light in a
completely
different way.

78. The interior of the glass bulb is coated with phosphors,
substances that emit light when they are bombarded with
electrical energy.

79. The color of a fluorescent lamp depends on the
particular makeup of its phosphor coating.

80. What is “phosphor?”

81. Fluorescent lamps do not burn, so they do not
have an actual color temperature, but they are
assigned an “apparent color temperature” to
indicate their degree of whiteness.

82. Fluorescent lights produce separate bands of energy instead of a continuous
spectrum, but will still emit all wavelengths at similar levels of energy. Because of
our eye’s sensitivity to yellow-green, ordinary fluorescent lamps appear yellow-
greenish.

83. Light that imitates sunlight - continuous spectrum - is sensed
as the most comfortable, welcoming and natural.

84. Some lamps are marketed as “full spectrum,” but that doesn’t
really tell you anything about the temperature of the light
since it could have various strengths of wavelengths.

85. Current emphasis on the environment has led to new
sources of light like the LED lamp.

86. LED lamps produce light at low operating cost by combining
the output of red, green light-emitting diodes.

87. LED lamps produce a white, strong light that is excellent for
limited uses like car headlamps, but is problematic in interior
environments because it contains only the three primary colors
and does not have a continuous spectrum.

88. Lighting level refers to the
quantity of available light,
regardless of its color makeup.

89. Lighting level describes the total amount of light
coming from the source and is unrelated to its
spectral distribution.

90. A lamp may give off more or less light, but its spectral distribution - the
pattern of energy emitted at the different wavelengths - is identical for
that lamp no matter what quantity of light it gives off.

91. Too little available light makes it hard to see colors.

92. Excessive and uncontrolled light falling on a surface can also
impair color perception.

93. Glare is an extreme, physically fatiguing level of
general light. Glare obliterates color perception and
can be temporarily blinding.

94. Reflectance or luminance is a measure of the amount of light
falling on a surface that is reflected back.

95. It is a measure of the total amount of light
reflected, not the individual wavelengths, or colors.

96. Reflectance is so
important to some
products, like interior
and exterior paints, that
the percentage of light
reflected back from
each color, called its
LRV (light-reflecting
value), is part of the
basic information the
manufacturer provides.

97. Lighting level affects our ability to see value, and to
make sense of what we see, but the color of the light
does not.

98. Vision is the sense that detects the environment and
objects in it through the eyes, and is the only way in
which color is perceived.

99. Color vision is experienced in two
different ways: either as light directly
from a light source, or as light reflected
from an object.

100. In the illuminant mode of vision, colors are
experienced as direct light reaching the eye, like the
colors of a monitor screen or a neon sign.

101. In the object mode of vision, colors are seen
indirectly as reflected light.

102. The tangible things of the real world - objects and the
environment - are seen in the object mode of vision.

103. The illuminant mode of vision has two
variables:
• the characteristics of the light
source
• and the characteristics of the
viewer.

104. In the illuminant mode of vision, colors are relatively stable.

105. But every viewer
brings their own
personal sense and
interpretation to the
perception of color.

106. Part 2

107. In the object mode of vision, color
is seen as light reflected from a
surface.

108. Color perception in the object mode of
vision has three variables:
• the characteristics of the light source,
• the individual viewer’s visual acuity for
color and interpretation of it, and
• the light-modifying characteristics of the
object.

109. Light leaving a light source is the
incident beam.
The reflected beam is light that
leaves a surface and reaches the eye.

110. The material an object is made of
modifies light in one of three ways:
• Transmission
• Absorption
• Reflection or scattering

111. Transmission:
the material allows light to pass
through, as through glass.

112. Absorption:
the material soaks up light reaching it like a sponge, and the
light is lost as visible. It can no longer be seen.

113. Reflection or scattering:
Light reaching the material bounces off it, changing direction

114. Colorants are special materials that modify light
by absorbing some wavelengths and reflecting
others.

115. A colorant can be integrated into the substance of
a material, like a color-through plastic...

116. ...or applied to a surface as a coating.

117. Colorants are also called color agents, dyes,
pigments, and dyestuffs, depending on their
makeup or end use.

118. A white colorant reflects, or scatters, all
wavelengths of light, and a black colorant absorbs
all of the wavelengths of light.

119. Other colorants modify light selectively.

120. Here the colorant in bananas absorbs all colors
except yellow which is reflected.

121. In order for an object to be seen as a color, the
wavelengths that its colorant reflects must be
present in the light surface.

122. A red dress seen under green light is a black dress.
In a parking lot illuminated by the light of yellow sodium lamps,
red, green and blue cars are indistinguishable from each other.
Only yellow cars can be located by their color.

123. Colorants don’t absorb and
reflect individual wavelengths
perfectly. They may absorb
part of a wavelength and
reflect part of it, or reflect
more than one wavelength.
So many possibilities exist
that the range of visible
colors is nearly infinite.

124. Colors seen as the
result of the
absorption of light
are subtractive
mixtures.

125. A Macbeth lamp has a spectral distribution
similar to sunlight and is often used under
laboratory conditions to measure color.

126. However, such a lamp has little use for artists
since their products are seen under all types
of light, and by all types of people.

127. Two objects that
appear to match
under one light
source but not under
another exhibit
metamerism. The
objects are called a
metameric pair.

128. Because materials differ in their ability to
absorb colorants or accept them as
coatings, it is virtually impossible to color
match two very different materials.

129. It is really only possible to reach an
acceptable match, one that is pleasing to
the eye.

130. If your colors are an acceptable match
under both fluorescent and incandescent
lights, they will probably be acceptable
under nearly all conditions.

131. A sample submitted for color matching is a
standard.

132. A match that is perfect under any light
conditions is possible only when the
original standard and the new product are
identical in all ways.

133. Surface is the outermost layer of a thing,
its “skin.”

134. Different surfaces - rough, smooth, or in
between - have an impact on the way that colors
are perceived.

135. Value refers to the relative lightness or
darkness of a hue.

136. Only the perception of value is affected by
surface texture.

137. Surface texture has no effect on hue, but a rough
surface will look darker than a smooth surface of
the same color.

138. The smoother the surface, the greater the
amount of light that is reflected back directly.

139. A specular surface is glossy, or mirror-like.

141. Light leaving a specular surface is reflected so
immediately, and so directionally, that most or all
of it is seen as white light.

142. When a specular surface is viewed from an angle
that is not the same as the angle of the incident
beam, some light reaching the underlying
colorant can be seen.

143. The color of a sequined garment is only visible
when the sequins are viewed at an angle that
allows the color to be visible.

144. A matte surface is a smooth surface that is very
slightly, even microscopically, roughened.

145. Colors on a matte surface have a flatness and
unifsormity under nearly all lighting conditions.

146. Textured surfaces are dynamic and lively.

147. Incident light scatters in random directions
producing a surface with both light and dark
patches.

150. Texture is most apparent under point light
sources, like sunlight or incandescent lamps.

151. Light from a point source originates from a
single location, or point, and the beams of light
emitted are parallel.

152. Fluorescent lights are linear light sources.
Linear light sources emit a broad-spread light
that is essentially non-directional

153. Light from a linear source does not reach the
surface at an angle in the same way as a point
light source.

154. Even heavily textured surfaces tend to appear
flat and uniform under fluorescent (or other
linear) lighting.

155. Point Linear

156. LED lamps are currently
offered as both linear
and point sources, but
LED lamps are an
emerging technology
and their rendition of
color and surface is
difficult to evaluate at
this time.

157. The sharper the angle of incident light,
the more directional the reflected beam
will be.

158. Raking light describes light from a source that is
positioned at an acute angle relative to a surface.

159. Specular surfaces appear more glossy, and
textured surfaces dramatically rougher, under
raking light.

160. Varying the textures of a surface allows designers to
create a an effect of two or more colors (or more
accurately, lighter and darker variants of a single hue)
using only one material.

161. A piece of yarn, seen on its long side, is relatively smooth. Cut
ends of the same yarn ( a pile, or nap) reflect the identical
wavelength but scatter light more widely and appear darker.

162. A small amount of light is lost each time that light travels
from a source to a surface, and when light reaches a
surface, a very small amount reflects back immediately.

163. The sum of this light loss can be so slight that as a practical
matter it is unimportant.

164. The light that remains is reflected, absorbed,
transmitted, or a combination of these.

165. If all of the light reaching an object is either reflected or
absorbed, the object is opaque.
If all (or nearly all) of the light reaching an object or
material is transmitted, that object is transparent.

166. When some of the light reaching an object or material is
transmitted and some is reflected, the object is
translucent.

167. A translucent material can be white or a color,
depending on its selective transmission and reflection of
various wavelengths

168. Translucent
materials may allow
a great deal of light
to pass through (and
be very translucent)
or transmit very
little light (and be
barely translucent).

169. The terms transparent and translucent are not
interchangeable. A truly transparent material is like
window glass: for all practical purposes, it is invisible.

170. A translucent material is detectably present, no matter how
sheer it may be.

171. Iridescence is an attribute of surfaces on which the hue
changes as the observer’s angle of view changes.

172. The changes from blue to green that are seen in a
butterfly’s wings as it flies...

173. the flashes of red, purple, and green in the black feathers of
a Grackle...

174. or the brilliant and changing colors of soap bubbles and oil
films are iridescence.

175. Iridescence is an
optical
phenomenon that
occurs with
reflected light.

176. The color is produced by the structure of a surface that
amplifies some wavelengths of light and suppresses others,
depending on the angle of the light reaching it.

177. The amplification
of light makes
iridescent color
extremely vivid –
the color that
reaches the eyes
may be reflected,
but in the absence
of a modifying
colorant it is
sensed as pure
light.

178. Because no colorant is involved – nothing that
absorbs some wavelengths of light and reflects
others – it is sometimes called structural color.

179. Iridescent textiles
are brilliantly
shimmery, seeming
to be one color at
one angle of view
and a second color
as the fabric moves.

180. Iridescence in
textiles is produced
in a variety of ways.
There are silk yarns
with a molecular
structure that
creates iridescence
as well as synthetic
yarns with similar
properties.

181. Most iridescent textiles, however, are made using special yarns
and techniques of weaving. When the warp and weft are made
from differently colored and light-reflective yarns, each color
appears, vanishes, and reappears as the viewing angle shifts.

182. There are paints and inks with light-reflecting properties that
create convincing iridescent effects on a page. As the
observer’s position changes, the color changes.

183. An impression of iridescence is difficult to create on a screen,
because light leaving a screen reaches the eye directly, no
matter what the viewer’s position or movements.

184. Luminosity is a word that appears
often in color study.
Its real meaning is the attribute of
emitting light without heat.

185. A luminous object is light-reflective,
but it does not emit heat.

186. The word “luminous”
is used often to
describe very light-
reflecting colors and
media with a great deal
of light reflectance, like
watercolor, dyes, or
markers.

187. Indirect light occurs when light from a light source
reaches a broad, light reflective plane that re-reflects it
onto a second surface or object.

188. In order for this to happen, the light source, the reflective
surface, and the target surface or object must be
positioned at similar angles to one another.

189. Moonlight is a familiar form of indirect light. The moon is
luminous: it reflects light but does not emit its own energy.
Its surface reflects the light of the sun to the earth.

190. Each time light travels, some of it is lost through scattering.
Moonlight is weaker than sunlight because much of the sun’s light
has been scattered and lost, first on its way from the sun to the
moon, then again from the moon to the earth.

191. Indirect light works in
the same way that
moonlight does. Light
reaching a white surface
is redirected to a target
area. The indirectly lit
area appears darker than
it would under direct
light, but no change in its
apparent hue takes
place.

192. Indirect color is a
form of indirect light.
Indirect color occurs
when general light
reaches a highly
reflective color on a
broad plane.

193. Some of the general
light–and a good deal
of the strong color–
will reflect onto any
surface that is
positioned to receive
it.

195. One way to describe the phenomenon of color
reflected from one surfact to another is
plane reflection.

196. The design applications most vulnerable to this are architecture and
interior design, where planes of color on walls, floors, and ceilings interact
with directional light sources to create potential conditions of light and
color reflections.

197. Filters are materials that transmit (pass through) some
wavelengths of light and absorb others.

198. A red filter placed between a light source and an object allows
only the red wavelengths to pass through. Other wavelengths are
absorbed.

199. Filters are powerful
modifiers of light, so
they must be used
with real
understanding of their
effects.