A change in in apparent brightness happens if you move closer and further from the screen.

 

The change in in apparent brightness happens whether the figure is brighter in the center (above)or darker (below).

 

 

The phenomenon works when different hues are used for the different spokes in the figure.

 

 

 

 

Effects are attenuated when equal-value stripes are used.

 

Another variant showing a strong effect.

 

The effect is stronger on the computer screen, but also works with printed versions, and even when the print is somewhat degraded by a copier.

The dimensions in the blue version were approximately 2 ft x 2 ft.