LESSON 1 - The Primary Colors of Light
- Use the primary colors of light to create new colors.
- Demonstrate their new knowledge of the primary colors of light by
coloring a diagram.
Worksheet 1 - Mixing Colors of
Light (1 per group)
Copies of blank venn diagram
Small flashlights (3 per group)
Red, blue, and green theatrical gels or cellophane
IMAGERS color mixing page at http://science.hq.nasa.gov/imagers/color
Show students the three flashlights. Ask them if they
can identify anything unique about this combination of colors. Explain
that todays activity will give them the opportunity to experiment
with colored lights.
Divide students into groups of four. Provide each group with
three flashlights, a red, green, and blue color theatrical gel, and
three pieces of tape. Each group should also have a copy of worksheet
1. Have students tape the gels around the face of the flashlight so
that no white light leaks out. Assign one to each student in the group.
One will be the recorder and three will hold a flashlight. Tell students
to use their flashlights to mix the colors of light. As they make
discoveries, ask the recorder to describe the color they created.
Have the group quantify the amount, or intensity, of colored light
used. (See directions and example on worksheet 1.) After a few minutes,
have the students exchange roles and continue mixing colors. (see
After students complete the chart, as a class discussion,
ask them to describe the colors they created. Make a list on the board.
(Optional: Use stage lights
to demonstrate the colors they name.) Review the following combinations
and give students the "proper names" for them.
Red + Green = Yellow
Red + Blue = Magenta (pinkish purple color)
Blue + Green = Cyan (turquoise)
Red + Blue + Green = White
The absence of light = Black
Then, ask students why red, green, and blue are so unique. Lead them
to understand that these three colors are the primary colors of light.
Explain that red, green, and blue mix to make all colors.
Distinguish the primary colors of LIGHT and the primary
colors of PIGMENT from each other. Red, green, and yellow are
the primary colors of PIGMENT, or paint and crayon. They cannot
combine to make the products of the primary colors of LIGHT.
(See venn diagrams.)
Relate this new information to computer monitors. Explain to
students that computer monitors combine red, blue, and green to make
the colors that we see. Our monitor can display hundreds and thousands
of colors. Give students a copy of the blank
venn diagram. Have them label and color in the diagram using the
information they learned in this lesson.
Ask students to name the primary and secondary colors
of light. Use the completed venn diagram to assess their understanding
of the primary color combinations.
Tips for Teachers
- Flashlights - Have each student bring in a flashlight for this activity.
Or, ask a local company to donate mini-flashlights.
- Color filters - Purchase a large sheet and cut it into small squares.
Or, find a theatrical store and ask for a filter swatch book. Make
sure to select a red, blue, and green filter combination that best
represents white when combined. Because filters are traditionally
used on high-powered stage lights, the exact same color filters used
for stage lighting may not produce the desired effects with low-powered
- Unlike adding more paint or crayon to get a darker color, adding
more colored light does not give a darker color. Higher numbers (amounts
of) will create a lighter color (i.e. all 9's equals white). Lower
numbers will create a dark color (i.e. 1,0,0 would be a dark red)
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