A recent viral video by Instagram user @ingrid.griffin is sparking major nostalgia and uncovering what she calls the ...

While violet hits your eye with a specific wavelength, purple only exists in your perception — a clever construct built from conflicting input.

The human eye does not ... a combination of blue and red wavelengths, the brain bends the visual spectrum into a circle that joins blue and red at the point of purple. You might be today years ...