### Worksheet: In Living Color

Name_______________________________________ Date_________________________

#### Color Vision

Put X's in the table to indicate which cones in the retina of the eye are stimulated by each color of light.

Color of light Red Green Blue
Red ______ ______ ______
Black ______ ______ ______
Cyan ______ ______ ______
Blue ______ ______ ______
White ______ ______ ______
Magenta ______ ______ ______
Yellow ______ ______ ______
Green ______ ______ ______

#### Color Television

What three colors are the tiny bars or dots on the screens of color televisions and computer monitors? _________, ___________, ___________ . Why are these three colors used?

How does the TV make yellow?

Write in the colors that you get when you mix these amounts of red, green, and blue in the program RGBtoHEX:

Red Green Blue Resulting color
0 0 0 ____________
0 0 255 ____________
0 255 0 ____________
0 255 255 ____________
255 0 0 ____________
255 0 255 ____________
255 255 0 ____________
255 255 255 ____________

#### 3. Color Spotlights

What color do you get if you overlap red, green and blue spotlights of equal brightness? ______

Challenge question: Suppose there was a Christmas Tree that had equal numbers of red, green, and blue lights, all equally bright. What color would this tree seem to be if you looked at it at night from very far away, so that you could not see the individual lights. Why?

Suppose the tree that had equal numbers of red, green, blue, yellow, and orange lights, all equally bright? What color would this tree seem to be from far away? Why?

#### 4. Making more colors

How many different colors could you make if you limit yourself to three values for each primary color - fully off (zero), half-on (127), and fully on (255)? _______ Complete the following table, entering 0, 127, or 255 under the Red, Green, and Blue columns to make all the different combinations. Make sure each color has a different name.

Red Green Blue Resulting color
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________
______ ______ ______ _________________

Can you think of a common color that is not in this table? _______ Try to make it in RGBtoHEX.exe. What mix of primary colors did it take? _________________

How many colors could be made if you limit yourself to four values of each primary color?

#### 5. What is the maximum number of colors that a computer can make?

If a computer uses 256 different values for each primary color, the total number of color combinations it can make is _______ x _______ x _______ = ________________

Why do computers make so many colors?

What is the difference between the two pictures of the green frog on the green leaf?

#### 6. Color printing: Mixing colors with ink

How does mixing colors on paper with ink differ from mixing colors of light on a TV screen?

When using the RGBtoHEX program, what happened when you removed one of the colors from white (set its slider to zero) while leaving the other two colors at 255?

What are the "process primary colors"?

What colors are used in the ink cartridge of an ink-jet computer printer?

In the Color Mixing Applet, what combination of ink colors and numbers do you need to create orange?

Why does color printing use different primary colors than color television or the human eye? Why not use red, green, and blue inks for color printing?

#### 7. Color painting: Mixing colors with paint

Why are cyan, magenta, and yellow a better set of primary colors for mixing paint or ink than the traditional combination of red, blue, and yellow?

Why did the painter George Seurat make his paintings with tiny dots of pure colour, rather than mixing paints like other painters?

#### 8. Color blindness

What is the most common type of color blindness?

Do boys or girls more commonly have some form of color blindness?

Were you able to see all the numbers in the color blindness test?