Color Mixing Simulation

Colors can be mixed in two different ways. Light adds: a screen makes every color by shining red, green and blue together, so red and green light make yellow and all three make white. Paint and printer ink take away: each color soaks up some of the light that lands on it, so red and yellow paint make orange, yellow and blue make green, and mixing all three gets darker and muddier. The same circles give a different answer depending on what is being mixed, which is why a school color wheel and a computer screen seem to disagree. Students can change red light and green light and compare what happens. Use it for physics inquiry with Grades 1–5 and Middle School on a projector or student device.

• Mix red and yellow paint, then yellow and blue, then red and blue, and name the three new colors
• Switch to light and mix red and green — find out why it makes yellow, not brown
• Turn all three lights up to full and see white, then do the same with paint and see the opposite
• Slide one color up while the other stays low and watch the mix shift gradually
• Switch to printer ink and find which pairs make red, green and blue

1. 1Predict how changing red light will affect the red value, then test the prediction.
2. 2Use evidence from the interactive visual to explain the result.

Questions teachers ask