File talk:Optical grey squares orange brown.svg

generally they are in the same surrounding, but specifically the squares are of different darkness shade (apart from the column shade)CuteHappyBrute (talk) 03:23, 28 October 2008 (UTC)

They are NOT the same colour!!
they are 2 totally differnt shades of grey! J (talk) 19:28, 3 February 2010 (UTC)
 * They are the same colour Don, check with a colour picker.124.254.78.121 (talk) 06:16, 21 April 2010 (UTC)

I don't think it is true to say that 'both circles' or 'both disks' are the same color. The ellipsis in the image may be the same color, but since one depicts an object in a shadow and one depicts a directly illuminated object, the object in the shadow must be an inherently lighter coloured object sorsoup (talk) —Preceding undated comment added 08:50, 27 August 2010 (UTC).
 * Not really, because this image is an illustration, it does not depict reality. There is no actual "object" in shadow, it is just a 2D image of shapes and colors. The key point is that our minds perceive it as representing a real situation, and that is where the illusion comes in. --129.11.249.211 (talk) 17:19, 21 October 2011 (UTC)