Color Systems – Additive and Subtractive
There
are two types of color systems, additive and subtractive. Subtractive
color is the physical mixing of paints, or pigments, to create a color.
It is called “subtractive” due to the fact that light waves are
absorbed (or subtracted from the spectrum) by the paint and only the
reflected waves are seen. A red pigment, therefore, is only reflecting
red light and absorbing all the others. In the subtractive system you
get black by mixing all the colors together—theoretically. It is a
challenge to mix pigments that result in a true black or a vibrant
color. That is one of the reasons art supply stores have so many
choices when it comes to paint. One of our advantages of working in the
additive system is that we can get consistent and vibrant results with
light. We won’t dwell on the subtractive system since we won’t be using
it.
The
additive system is when light is added together (like on a computer
screen) to create a color, so naturally we deal with the additive
system as computer artists as we are working with light. In Figure 1-18
you can see how the additive system works. I simply went into Max and
created three spotlights that were pure red, green, and blue and
created my own Additive Color Wheel, or a visual representation of how
the colors interact. Black is the absence of light (the area outside of
the spotlights), White is all light (the center area where all three
lights overlap each other)—the combination of red, green, and blue is
the additive system. If you look at the Color Picker in Photoshop
(Figure 1-19) you will see a vertical rectangle of color graduating
from red through the colors and back to red. This allows you to select
a Hue and use the Color Picker Palette to change the value and
intensity.
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Figure
1-18: The additive system works by adding lights. Black is the absence
of light (the area outside of the spotlights), White is all light (the
center area where all three lights overlap each other): the combination
of red, green, and blue is the additive system.
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Figure
1-19: The Color Picker in Photoshop has a vertical rectangle of color
graduating from red through the colors and back to red. This allows you
to select a hue and use the Color Picker Palette to change the value
and intensity.
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Primary Colors
The
three primary colors in the additive color system are red, green, and
blue (RGB). They are referred to as primary colors because you can mix
them and make all the other colors, but you can’t create the primary
colors by mixing any other color. Many projection televisions use a
system where you can see the red, green, and blue lens that project the
three colors (RGB) to create the image you see using the additive
method.
Secondary Colors
The
secondary colors are yellow, magenta, and cyan. When you mix equal
amounts of two primary colors together, you get a secondary color. You
can see that these colors are located between the primary colors on the
color wheel and on the Photoshop Color Picker vertical strip.
Color Emphasis
Color
is often used for emphasis. Look at Figure 1-20. All things being
equal, the larger shapes dominate, but the small shapes demand your
attention once color is added. Of course, there are many other forms of
emphasis you can use in creating art, but color can be the most
powerful—and overused. Ever come across a web page that has a busy
background and every font, color, and emphasis devised by man splashed
across it? There is almost no emphasis as all the elements cancel each
other out. Often, less is more.
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Figure
1-20 All things being equal, the larger shapes dominate, but the small
shapes demand your attention once color is added.
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In
another example using a photograph, in Figure 1-21, you can see that in
the first black and white photo, your eye would most likely be drawn to
the dark opening of the doghouse and you would most likely assume that
the subject of this picture is the doghouse. In the second version the
colorful flower draws the primary interest, it still competes with the
doghouse door for attention, but you would probably make the assumption
that the focus of this picture was the flower.
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Figure
1-21: Your eye is most likely drawn to the opening of the doghouse in
the black and white photo, but add color, and the flower draws the
primary interest.
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In
a game scene you can see the use of color drawing the attention of a
player to an important item. Look at Figure 1-22. In the first version
of the scene you are drawn to the fire and then look around at all the
items in the shadows. In the second version the red crate draws your
attention and clearly means something. Depending on the world logic of
the game you are playing, that could simply mean that you can interact
with the object, or it could mean the item is dangerous. That decision
brings to our next topic, color expression.
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Figure
1-22: In a room full of normal objects, the players’ eyes will be
drawn to the fire and then equally to the objects. In a room full of
normal objects, a red crate draws attention, especially given the fact
that there are other normal crates around it.
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Color Expression or Warm and Cool Colors
When
you start painting textures and choosing colors, you will want to know
how they react together in terms of contrast, harmony, and even
message. There is a lot of information on this topic and once again,
Johannes Itten enters the picture (the guy who did the color wheel).
Johannes Itten has provided artists with a great deal of information on
how color works and how they work together. Itten was among the first
people to look at color, not just from a scientific point of view, but
from an artistic and emotional point of view. He was very interested in
how colors made people feel. From his research we get the vocabulary of
warm and cool colors.
We
all are familiar with this convention as it is mostly based on the
natural world. When asked to draw a flame, we reach for the red or
orange crayon, ice is blue, the sun yellow. Each warm and cool color
has commonly associated feelings for them, both positive and negative.
The brighter or more pure the color, the more positive the association.
Darker and duller colors tend to have the negative connotations
associated with them.
The
warm colors are red and yellow, while the cool colors are blue and
green. Children will color the sun yellow and ice blue and use the
black crayon to scratch out things they don’t like. Traffic lights are
hot when you should stop or be cautious (red and yellow) but cool when
it is okay to go (green). Red and orange are hot and usually associated
with fire, lava, coals. How many red and black shirts do you see at the
mall? Red and black generally symbolizes demonic obsession. Red by
itself can mean royalty and strength as well as demonic. Deep red can
be erotic. Yellow is a hot color like the sun, a light giver. Yellow is
rich like gold as a pure color. A deep yellow (amber) window in the
dark of a cold night can mean fire and warmth. But washed out or pale
yellow can mean envy or betrayal. Calling a person yellow is an insult,
meaning he is a coward. Judas is portrayed as wearing yellow garments
in many paintings. During the Inquisition, people who were considered
guilty of heresy were made to wear yellow. Moving into green, we think
of lush jungles teaming with life. As green washes out, we get a sense
of dread and decay (zombie and orc skin). Vibrant green in a certain
context can be toxic waste and radioactive slime. Blue in its saturated
state is cold like ice, fresh like water and the sky. Darker blues are
misery. Purple is mysterious and royal.
Keep
in mind that color is context-sensitive. Water is generally blue; would
you drink dark green water? But not just any blue will do. In the real
world, if we come across water that is a saturated blue that we can’t
see through, we get suspicious. Was this water dyed? Are there weird
chemicals in there? If anything lives in that, then what could it be?!
Blood is generally red, but what if an enemy bled green? What if the
game you are playing is about an alien race taking over earth and one
of your companions bleeds green from an injury during combat? In a
fantasy game you might come across coins. Which coin do you take, the
bright yellowish metal or gray-green metal? With no previous
information on the color of coins in this world, most people would pick
the brighter yellow. Look at Figure 1-23. What are some of the
assumptions you might make about these three scenes?
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Figure
1-23: These three scenes are the same, except for the ax. What
questions and/or assumptions run through your mind looking at each
version?
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Looking
at color in this way may make it seem a bit mechanical, but it still
takes a talented artist to make the right color choices. You can
memorize all the information in the world, but it usually comes down to
having a good eye and being able to convey that vision in your work and
to your coworkers.