Color by Reflection

What do PIGMENTED OBJECTS look like under monochromatic lights?

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Try This

The color of light sources influences the way we perceive objects. For example, if the sun was truly only pure yellow, we would only see the world in shades of yellow! The fact that we can see objects of a full rainbow of colors suggests that the sun, is, indeed, producing the full visible spectrum of light.

 

Use the Color Generator tool to produce a single color of light, such as red. In a completely darkened room, shine the pure red screen down on a set of colored candies, Lego blocks, or beads (simple colors work best, such as red, blue, green, and yellow). Attempt to sort the items into similarly-colored groups. Then, turn on the ambient light and see how successful you were! Mix up the candies, and try again with pure blue and green, and then secondary colors of light (yellow, magenta, and cyan). Keep track of which colored candies are easiest to sort under which colors of light, and come up with a potential explanation for why this is the case.

 

Challenge Yourself

• Complete the student worksheet listed in "Resources" below.

• Attempt to predict the colors that a given color of candy will appear to your eye when observed under a specific color of light.

• Using a print-out of the South African flag, sketch what you expect the flag will look like under white, red, blue, green, yellow, magenta, and cyan light.

 

Related Resources

• Rebecca Vieyra. "M&M's Color Sorting Lab."

• Bree Barnett-Dreyfus: "Color Subtraction: Reflected Color"