1. Color

2. Visible Light Spectrum
“Newton divided the spectrum into seven named colors: red, orange, yellow, green, blue, indigo, and violet. (Some schoolchildren memorize this order using the mnemonics ROY G. BIV.) He chose seven colors out of a belief, derived from the ancient Greek sophists, that there was a connection between the colors, the musical notes, the known objects in the solar system, and the days of the week.[5][6] The human eye is relatively insensitive to indigo's frequencies, and some otherwise well-sighted people cannot distinguish indigo from blue and violet. For this reason some commentators, including Isaac Asimov, have suggested that indigo should not be regarded as a color in its own right but merely as a shade of blue or violet.” – WIkipedia
There are really only 6 but several reasons why 7 was promoted:
Newton was a numerologist and liked 7 over 6
Religious influences like 7 (holy) over 6 (devil)
Indigo was gaining in popularity, a more expensive “purple” dye from India
Notice that red has a wavelength longer than violet; which means what? (it has a smaller frequency)
Violet is therefore the more energetic color (=AV>FHS)
700 nm nm

3. Primary Colors Red Green What are the primary colors? Are you sure?
Continuing into color, ask students to recall what their kindergarten teachers told them the three primary colors were. (you will inevitably hear “yellow”)
You can overemphasize this fact by saying, “Your Kindergarten teachers lied to you!”
Red
Green
Blue

4. Color Addition
By adding the same intensities of the Primary colors (Red, Green and Blue) you can create white light
White light is all primary colors added together
Red + Green + Blue = White
Pass around “XLight” which cycles through three LEDS (R, G, B) and overlaps them so that you can see color addition

5. Secondary Colors G + B = C R + B = M R + G = Y
Primary colors mixed in pairs create three additional colors called Secondary Colors (Cyan, Magenta, and Yellow)
G + B = C
R + B = M
Ask students which two primary colors will be added together to make each. They will not believe you with yellow!
R + G = Y

6. Complementary Colors because (R+G) + B = W
Two colors are said to be complementary colors if they can be combined to make white light
For example, the primary color blue and the secondary color yellow
R + G = Y so Y + B = W
because (R+G) + B = W
Different than complementary colors for art (colors opposite on the color wheel)
By substitution, its as if you added all three primary colors

7. TV Screens

8. Have students use magnifying glass

9. Mix all three primary colors = white
Mix two of the primary colors = secondary

10. Frequently used in theater work for effects.

11. Notice that students appear normal, even their white sweatshirts.

12. Colored Shadows show the colors hidden in white light
Colored Shadows show the colors hidden in white light. Red, green and blue spotlights shine on a wall. The wall looks white because red, blue and green light combine to make white light. As you walk in front of the lights, your bodies cast three different shadows.
Wherever a shadow blocks one color of light, the other two colors combine to make a new complementary color. A person standing close enough to the wall can create six different colors, plus black and white.
Have students read (or read to them) BUT tell them NOT to copy it down!

13. Shadows are made in the secondary colors of light, each by blocking one of the three primary colored light sources.

14. You can see the primary colors of light when two (secondary colored) shadows overlap. When all three overlap you see black (or absence of light)

15. Color Subtraction
Something appears Yellow if it reflects Yellow light (of that wavelength) and absorbs the rest
Point to different students in different colored shirts to review.
Example:
Jimmy has a red shirt on. What color(s) is his shirt reflecting? (red) What color(s) is his shirt absorbing? (blue & green)
Do they need?
A dye is a molecule that absorbs certain wavelengths and transmits (reflects) other wavelengths
A pigment is larger than a molecule but does the same thing

16. Subtractive Colors Additive Colors Applies to Light Sources
Point out that the primary colors of light are NOT the same as the primary pigments – this will be emphasized again later.
Point to each primary pigment (CYM) and ask which color is it absorbing?
Y=W-B
C=W-R
M=W-G
Notice that the color its absorbs is opposite it in that diagram.
Applies to Light Sources
Computer Monitors
Emitted Light
Applies to Reflected Light
Printed Images
Pigments & Paint

17. flashLIGHTS add colors of LIGHT
Paints use subtractive Pigments

18. Color Printers work by mixing pigments
Color Printers work by mixing pigments. They add cyan, magenta, yellow and black to create the colors we are used to.
When you buy a cartridge package you buy a “CMYK” which is “Cyan, Magenta, Yellow & black)

19. Demo with overhead with “owl” painting & palace of fine arts
Demo with overhead with “owl” painting & palace of fine arts. Build up one color at a time and then add black. Demonstrate how the colors change by removing one overhead.