Find shared channels
Yellow and cyan filters share green, so their combination passes green light.
Color Filter Lab
Send colored light through two filters and track the channels that survive.
Grades 3–5 · Physics
Your goal
Start with white light and use 1 colored filter to make yellow. White means clear.
Reduced motion is on. The controls still update the scene.
The screen shows white. Red, green and blue channel amounts are 1, 1, 1. Filters absorb missing channels. A later filter cannot restore a channel already removed.
This ideal three-channel model treats each filter as completely passing or absorbing each red, green or blue channel. White source light contains all three; a white filter is clear. Absorbed light transfers energy to the filter rather than becoming another light color. Real filters have gradual wavelength bands and may pass less light. Channel bars show presence, not perceived brightness.
Related resources
Related simulations
Related tools
Related worksheets
Study as flashcards
Related infographics
Learn with Color Filter Lab
Color Filter Lab gives elementary students a visible way to investigate selective transmission. Choose a light source and place two filters in its path, then follow the separate red, green and blue channel bars toward the screen. A clear filter passes every available channel, while colored filters remove selected channels. Try combinations that leave one color or block the light completely. Guided challenges encourage learners to reason from the source through both filters and explain why a later filter cannot restore light that an earlier filter absorbed.
What to look for
Remember the source
A filter cannot transmit a channel that was missing from the incoming light.
Try making darkness
A red source and a cyan filter share no channels in this ideal model.
For teachers and curious learners
Discover that color filters absorb selected light channels rather than adding colors. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Ideal filters completely pass or absorb three red, green and blue channels. White means all channels at the source and a clear filter. Real spectral bands, partial transmission and perceived brightness are not modeled.