Each band is uniformly shaded, but band boundaries appear wavy. Mach banding is the result of inhibitory interconnections between retinal neurons of the eye. Retinal neurons exposed to comparatively intense (bright) areas inhibit the response of neurons in their proximity. On the band boundaries, this suppresses the visual signal to the left of the transition, making it appear darker. The presence of a darker area next to a lighter area means less inhibitation to the brighter area, making it appear lighter.

The model is white, but it changes colour when the light source illuminating it changes colour. Our brains compare surrounding visual cues with our memory of colour. Were we in the same room as this mobile, we would still see that it is green, but we would also be able to perceive that it is white.

When we stare at a coloured square over a dark background, and then stare at a plain white field, an after image of the square will appear. The after image will be in the complimentary colour of the original colour. Click on the image to the left and stare at the yellow block. At about 15 seconds, the image will abruptly change to a solid white background. Stare at the white background and you should see a purple square. Note that this effect depends a lot on the brightness of the monitor, ambient light, and the condition of your eyes.