1. Color Objectives Explain perception of color
Describe Selective Reflection and Selective Transmission
Explain Mixing Colored Light and Mixing Colored Pigments
Tell Why the Sky Is Blue, Sunsets Are Red, Clouds Are White, and Water Is Greenish Blue

2. White light is the combination of all colors of light

3. Color in Our World Color we see depends on frequency of light.
Lowest frequency—perceived as red
In between lowest and highest frequency—perceived as colors of the rainbow (red, orange, yellow, green, blue, indigo, violet)
Highest frequency—perceived as violet
Beyond violet, invisible ultraviolet (UV)
Below red, invisible infrared

4. What can the human eye not see?
Color
What can the human eye not see?
A. Infrared radiation
Ultraviolet radiation
Both A and B.
Neither A nor B.
C. Both of the above.

5. What can the human eye not see?
Color
CHECK YOUR ANSWER
What can the human eye not see?
A. Infrared radiation
Ultraviolet radiation
Both A and B.
Neither A nor B.
C. Both of the above.

6. Selective Reflection
The color of an opaque object depends on reflection
Objects reflect some frequencies and absorb the rest.
Rose petals absorb most of the light and reflect red.
Objects that absorb light and reflect none appear black.
Objects can reflect only those frequencies present in the illuminating light.

7. Selective Transmission
Color of transparent object depends on color of light it transmits.
Colored glass is warmed due to the energy of absorbed light illuminating the glass.

8. Sunlight The sun gives off all frequencies of light
Distribution of solar frequencies is uneven.
Most intense in yellow-green portion

9. Mixing Colored Light
Radiation curve divides into three regions that match the color receptors in our eyes.

10. Mixing Colored Light Additive primary colors: Red, green, and blue
Produce any color in the spectrum

11. Red, green, and blue light overlap to form
Mixing Colored Light
Red, green, and blue light overlap to form
A. red light.
green light.
blue light.
white light.
D. white light.

12. Red, green, and blue light overlap to form
Mixing Colored Light
CHECK YOUR ANSWER
Red, green, and blue light overlap to form
A. red light.
green light.
blue light.
white light.
D. white light.

13. Mixing Colored Light
When the color yellow is seen on your TV screen, the phosphors being activated on the screen are
A. mainly yellow.
blue and red.
green and yellow.
red and green.
D. red and green.

14. Mixing Colored Light CHECK YOUR ANSWER
When the color yellow is seen on your TV screen, the phosphors being activated on the screen are
A. mainly yellow.
blue and red.
green and yellow.
red and green.
D. red and green.

15. A blue object will appear black when illuminated with
Mixing Colored Light
A blue object will appear black when illuminated with
A. blue light.
cyan light.
yellow light.
magenta light.
C. yellow light.

16. A blue object will appear black when illuminated with
Mixing Colored Light
CHECK YOUR ANSWER
A blue object will appear black when illuminated with
A. blue light.
cyan light.
yellow light.
magenta light.
C. yellow.

17. Mixing Colored Light Subtractive primary colors
Combination of two of the three additive primary colors:
red + blue = magenta
red + green = yellow
blue + green = cyan

18. Mixing Colored Light The shadows of the golf ball are subtractive.
Magenta (opposite of green)
Cyan (opposite of red)
Yellow (opposite of blue)

19. Mixing Colored Pigments
The subtractive primary colors are cyan, yellow, and magenta.
white light through overlapping sheets of these colors, light of all frequencies is blocked (subtracted) and we have black.
cyan and yellow overlap, light of all frequencies except green is subtracted.
Various proportions of cyan, yellow, and magenta dyes will produce nearly any color in the spectrum.

20. Color Printing
Only three colors of ink (plus black) are used to print color photographs—(a) magenta, (b) yellow, (c) cyan, which when combined produce the colors shown in (d). The addition of black (e) produces the finished result (f).

21. Why the Sky Is Blue Results of scattering light waves
Higher the frequency of light is scattered more.
Our eyes are more sensitive to blue than violet

22. Effect of weather on sky color
Varies in different locations under various conditions:
Clear dry day—much deeper blue sky
Lots of dust particles and larger molecules than nitrogen and oxygen in the atmosphere—less blue sky with whitish appearance
After heavy rainstorm (washing away of airborne particles)—deeper blue sky

23. A white sky is evidence that the atmosphere contains
Why the Sky Is Blue
A white sky is evidence that the atmosphere contains
A. predominantly small particles.
predominantly large particles.
a mixture of particle sizes.
pollutants.
C. a mixture of particle sizes.

24. A white sky is evidence that the atmosphere contains
Why the Sky Is Blue
CHECK YOUR ANSWER
A white sky is evidence that the atmosphere contains
A. predominantly small particles.
predominantly large particles.
a mixture of particle sizes.
pollutants.
C. a mixture of particle sizes.

25. Why Sunsets Are Red Low frequencies scatter least
At sunset/sunrise the light travels through more atmosphere than at noon

26. A variety of sunset colors is evidence for a variety of
Why Sunsets Are Red
A variety of sunset colors is evidence for a variety of
A. elements in the Sun.
apparent atmosphere thickness.
atmospheric particles.
primary colors.
C. atmospheric particles.

27. A variety of sunset colors is evidence for a variety of
Why Sunsets Are Red
CHECK YOUR ANSWER
A variety of sunset colors is evidence for a variety of
A. elements in the Sun.
apparent atmosphere thickness.
atmospheric particles.
primary colors.
C. atmospheric particles.

28. Why Sunsets Are Red
If molecules in the sky scattered orange light instead of blue light, sunsets would be
A. orange.
yellow.
green.
blue.
D. blue.

29. Why Sunsets Are Red CHECK YOUR ANSWER
If molecules in the sky scattered orange light instead of blue light, sunsets would be
A. orange.
yellow.
green.
blue.
Explanation:
Of the colors listed, blue is closest to being the complementary color of orange.
D. blue.

30. Why Clouds Are White
Clouds are clusters of various sizes of water droplets
Light scattered determines cloud color.
Tiny clusters - bluish clouds.
Slightly large clusters - greenish clouds.
Larger clusters - reddish clouds.
Overall result is white clouds.
Slightly larger clusters produce a deep gray.
Still larger clusters produce raindrops.

31. Why Water Is Greenish Blue
Water molecules absorb red light
When red is removed from white light, the complementary color of red remains: cyan—a bluish-green color.