Neon Color Spreading
Look at the center circle. Does the white space inside look faintly blue/cyan? It's actually pure white.
The Filling-In Effect
✨ Subjective Contours▼
This illusion, similar to the Kanizsa Triangle, demonstrates **filling-in**. The brain detects the colored segments and assumes they belong to a transparent colored object sitting *on top* of the black grid.
To make this interpretation consistent, the brain hallucinates a faint wash of color over the empty white space, creating a "neon" glow.