Additive Primary Colors
and Subtractive Primary
Colors
Parkland Junior High School
2012-2013
Color and Vision
• When all the colors of the rainbow are combined, we do not
see any particular color. All we see is light without any color.
• We call this combination of all the colors of light
light”.
"white
How we see color
• The retina of the human eye contains two types of cells that respond to
light.
1. Cells called Rods detect the presence of light.
2. Cells called Cones detect color.
1.
There are 3 types of cones, each type of cone responds to a different color.
How we see color.
• The cones in the human eye respond mainly
to red, green, and blue light. This is why the
eye can be tricked into thinking that a beam of
light is white when it contains only those three
colors. This is also why all other colors are
seen by the eye in terms of the relative
amounts of red, green, and blue light sensed
by the cones.
• Signals form all 3 types of cone cells and rod
cells travel along the optic nerve to the brain.
The brain interrupts the shape and color of an
object you see.
Color Blind?
• If a person has
defective cone cells.
They have difficulty
detecting some colors.
This is know as colour
blindness.
Color blind impressions
Additive Colors
• We see with our eyes the colors
created by the natural light in the world.
These colors are known as additive
colors. The term "additive" refers to the
mixing of light.
• First described by James Clark Maxwell
in the mid 1800s, the Color Additive
Theory describes how we perceive
color and how they are created.
Additive Primary Colors
•
•
Essentially white light is a
combination of many
different colors, a
continuum of wavelengths
organized into “bands”
which we label with names
(blue, green, red, etc.)
When equal amounts of red
light, green light, and blue
light are mixed together
they produce white light.
Because you add the colors
together to get white the
colors that are added are
known as the Additive
Primary Colors.
Additive Primary Colors
• Red, green, and blue
(RGB) are known as
the additive primary
colors of white light.
• The light of two
additive primary colors
will produce a
secondary color.
• The secondary colors
are yellow, cyan, and
magenta. These are
the “additive”
combinations.
The use of additive primary colors in everyday life, e.g.
computer monitors, televisions, and human vision.
Subtractive Primary
Colors
• So, if one of the additive primaries are
removed, the color of the light
changes. For example, if the red light
were removed, equal amounts of blue
and green light would make cyan light.
Equal amounts of green and red light
would make yellow light, and equal
amounts of red and blue light will make
magenta light.
Subtractive Primary
Colors
•
•
Yellow, cyan, and magenta
(CMY) are called subtractive
primary colors because some
portion of white light has been
removed in order to produce
each color.
When all 3 subtractive primary
colors are combined they
produce black
The use of subtractive primary colors in everyday life, e.g.
color printers and printer color ink
Answer the following...
The three initial colours used are called the
primary additive colours. What are they?
2. What secondary colours were created when only
two of the primary colours were blended?
3. What colour was created when all three primary
colours were combined?
4. What colour was created when all three secondary
colours were combined?
1.
Answers...
1.
2.
3.
4.
(blue, red, and green)
(magenta, cyan, yellow)
(white)
(black)
Free powerpoint template: www.brainybetty.com
15
• https://www.youtube.com/wat
ch?v=BoP_mnzE57c
• https://www.youtube.com/wat
ch?v=I4pgO3U5luY&list=PL7
28394DC585ACD0D
•
Free powerpoint template: www.brainybetty.com
16