This Demonstration lets you explore the effect of changing the colors of three optical illusions: the neon color spreading illusion, the scintillating dot illusion, and the Hermann illusion. The neon color spreading illusion creates seemingly circular dots at the colored crosses of the grid intersections. The scintillating dot illusion produces dark dots that appear and reappear. The Hermann grid illusion produces dark, "ghostly" dots at the intersections of the white lines. Depending on the vibrancy, darkness, or lightness of the selected hue, the dots may or may not appear.