Interactive Color Mixer
Mixing light is not the same as mixing paint, and this mixer shows the difference. Overlap red, green and blue beams and the result gets brighter, ending at white — the opposite of what happens with pigments.
How to use this simulation
- Set the intensity of the red, green and blue channels
- Overlap the beams to see the secondary colours
- Read the resulting RGB value
What to look for
- Red and green together give yellow, which surprises most people
- All three at full strength give white, not black
- Turning every channel to zero gives black — the absence of light
The physics behind it
Additive mixing applies to light sources: red, green and blue are the primaries because human eyes have three cone types tuned near those wavelengths. Combining all three at full intensity stimulates every cone equally and reads as white. Screens work this way, which is why every pixel is an RGB triple.