Light Waves
•Today’s Topics
Color Addition - Light
Color Subtraction – Pigment
Color of water
Color of the Sky
Additive Color
Which of the following is
NOT a primary color of light
Blue
Yellow
Red
Green
Which of the following is
NOT a primary color of light
Blue
Yellow
Red
Green
What color is produced
when red light is added to
green light?
Magenta
Cyan
Yellow
white
What color is produced
when red light is added to
green light?
Magenta
Cyan
Yellow
white
Which of the following color
combinations will produce magenta
light
Red and blue
Green and red
Blue and green
Red and white
Which of the following color
combinations will produce magenta
light
Red and blue
Green and red
Blue and green
Red and white
Which of the following color
combinations will produce cyan light
Red and blue
Green and red
Blue and green
Red and white
Which of the following color
combinations will produce cyan light
Red and blue
Green and red
Blue and green
Red and white
Which color do you need to
mix with cyan to produce
white light?
Red
Blue
Green
yellow
Which color do you need to
mix with cyan to produce
white light?
Red
Blue
Green
yellow
Complimentary Colors
These are two colors when mixed,
produce white light
The compliment to cyan is ‘red’
The compliment to magenta is ‘green’
The compliment to yellow is ‘blue’
Summary
Mixing all the colors of LIGHT give us
what color?
Summary
Mixing all the colors of LIGHT give us
what color?
WHITE LIGHT
The theory of color
The reason why we see things is that
light goes from the object to our eyes
The theory of color
The reason why we see things is that
light goes from the object to our eyes
The color we see is due to absorption
and reflection
The theory of color
The reason why we see things is that
light goes from the object to our eyes
The color we see is due to absorption
and reflection
White light is made up of the full
ROYGBIV
Theory of Color
Newton discovered that white light
split apart gives us the ROYGBIV by
accident
Why do we see something
blue in white light?
Why do we see something
blue in white light?
The object absorbs all the colors
except blue, it reflects blue to our eyes
Why does a white shirt
appear white in white light?
Why does a white shirt
appear white in white light?
It reflects all colors and absorbs none.
This is why white is a summer color,
to help keep you cool by not absorbing
the suns rays.
What color would a white
shirt appear if we only
shined red light on it?
What color would a white
shirt appear if we only
shined red light on it?
It would appear RED. White reflects
all colors.
Think about your screens!
What color would a RED
shirt appear if we only shine
RED light on it?
What color would a RED
shirt appear if we only shine
RED light on it?
RED… A red shirt reflect RED light!
Subtractive Color
When all frequencies of light
are absorbed, what color
results?
Black
White
Cyan
Red
When all frequencies of light
are absorbed, what color
results?
Black
White
Cyan
Red
Which color is produced when
yellow & cyan paint are mixed?
Blue
Red
Green
Black
Blue
&
Green
Green
&
Red
Which color is produced when
yellow & cyan paint are mixed?
Blue
Red
Green
Black
Which color is produced when
yellow & magenta paint are
mixed?
Blue
Red
Green
Black
Green
&
Red
Red
&
Blue
Which color is produced when
yellow & magenta paint are
mixed?
Blue
Red
Green
Black
Which color is produced when
cyan & magenta paint is mixed?
Blue
Red
Green
Black
Green
&
Blue
Blue
&
Red
Which color is produced when
cyan and magenta paint are
mixed?
Blue
Red
Green
Black
What two pigments can you
combine to produce the color
black?
Cyan & magenta
Magenta & yellow
Green & magenta
Cyan & yellow
What two pigments can you
combine to produce the color
black?
Cyan & magenta
Magenta & yellow
Green & magenta
Cyan & yellow
Why does a black shirt
appear black in white light?
Why does a black shirt
appear black in white light?
It absorbs all colors and reflects none.
This is why dark colors are for winter
times so it can help keep you warm by
absorbing the suns rays.
What color would a blue
shirt appear if we ONLY
shined red light on it?
What color would a blue
shirt appear if we ONLY
shined red light on it?
BLACK…A blue shirt absorbs ALL of
the colors (including RED) and only
reflects blue.
If we only shine red light on it, it will
absorb all the light incident on it and
will appear black!
What would you see if we only
shined red light on this picture?
What color would the blue writing
appear?
What color would a blue shirt
appear if we only shined red
light on it?
Black!
What about if we only shine
blue light?
What color will the red appear?
What about if we only shine
blue light?
What color will the red appear?
Why do large bodies of water
appear bluish-green?
Why do large bodies of water
appear bluish-green?
Red light gets absorbed first (actually
in the first 10 m) and you see what is
left (blue and green) Cyan.
Why is the sky blue?
Why is the sky blue?
It cannot be because the sky reflects
from the water. If it did , what color
would the sky be over large bodies of
land? (brown/green…)
Why is the sky blue?
It cannot be because the sky absorbs
all colors except blue, it reflects blue.
How would we be able to see all the
different colors outside if this were the
case?
Why is the sky blue?
It must be a different phenomenon. It
is called SCATTERING.
The small particles are resonating and
giving off high frequencies of light
(blue/violet)
Why does the sun appear
yellow, when it is actually
white light?
Why does the sun appear
yellow, when it is actually
white light?
Since the sky is blue, what color do
you get when you subtract blue from
white?
Yellow (compliment)
Why are nice clouds white,
while mean storm clouds are
dark?
Why are nice clouds white,
while mean storm clouds are
dark?
The nice clouds are made of all
different sized particles which scatter
all colors of light (white)
Why are nice clouds white,
while mean storm clouds are
dark?
The nice clouds are made of all
different sized particles which scatter
all colors of light (white)
Storm clouds are filled with water
which absorb light. What color do
things appear if light is being
absorbed?.....Dark!
Why are sunsets red?
Why are sunsets red?
The sun is at such an angle, that the
suns rays are traveling a longer
distance through out atmosphere
scattering all the blue range light and
we view what is left after all the blue
energy is used up.
Purple Skies ?!?
After sunset, the reddened evening
sunlight illuminates small particles in
higher altitudes (10 km to 20 km) in
the lower stratosphere.
– This reddish light combines with blue
scattered light to provide a purplish hue.
Light is very cool
Can you dig it?