Gizmos Student Exploration: Subtractive Colors

Gizmos: Subtractive Colours
Name: Date:

Prior Knowledge Questions

(Do these BEFORE using the Gizmo.)

A color printer can print any color by mixing three primary
colors of ink: cyan (light blue), magenta (bright pink), and
yellow.

1. What color do you think you would get if you mixed cyan and magenta? Blue

2. What color do you think you would get if you mixed cyan and yellow? Green

3. What color do you think you would get if you mixed magenta and yellow? Red

Gizmo Warm-up
We see objects when light from that object enters our eyes. Some objectsproduce
their own light, while others transmit or reflect light. The Subtractive Colors
Gizmo allows you to explore how light is absorbed and reflected by colored
pigments such as paint.

Three primary colors of light—red, green, and blue—combine to make white
light. Turn on Show RGB values at the mouse location to see how much
red, green, and blue is in each color.

1. Move the cursor over a white area. What is the RGB value of white?255,
255, 255

2. Move the cursor over the cyan circle. What is the RGB value of cyan? -0, 255,
255

3. Assume the cyan circle is a painted spot that is illuminated by white light. Some of the white
light is absorbed by the cyan pigment, and some is reflected into your eyes.

A. What colors of light are reflected by the cyan spot? Green, Blue

B. What color of light is absorbed by the cyan spot? Red

Activity A: Get the Gizmo ready:
Mixing primary ● Turn on the Cyan, Magenta, and Yellow circles.
colors ● Check that each color value is set to 255.