Weekend Diversion: An Optical Illusion

Starts With A Bang! is off to a great start; each the past three days we have topped the 100 visitor mark, bringing our total number of unique visitors up to 1,413! I'm going to attempt to start a new tradition here of making a weekend post on a topic that I just find neat, and share it with you. This first Weekend Diversion is an optical illusion about color. Take a look at the image below:

Looks like a cube with a bunch of different colors on it. Now do the following:

  1. Look at the top face of the cube, and tell me what color the tile in the middle of that face is.
  2. Look at the near face, and tell me what color the tile in the middle of that face is.

Did you answer the first question as brown? Did you answer the second question as yellow? Yes yes, I know, we all know our colors. (Colours, for you international readers.) But are you sure that you're right? Why don't we take that image and remove everything except those two tiles, and let's see what we get:

They're actually the same color as one another! The skeptics among you might think I photoshopped or edited it, so go ahead and try cropping or editing the top image for yourself! Why do we see brown on top and yellow on the side? It's because the perceived color of an area is affected by its surroundings. This is explained and demonstrated in beautiful detail here. Enjoy your weekend, and keep sending in your questions!

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Actually they are not the same color. You can use a simple utility that will tell you the color of a specific pixel. I ran the utility just to check, and the two tiles you speak of are actually different colors. This WOULD be true if it was a physical object. Our minds will make us think they are different colors, when in reality, they are the same. In the images you have above, the pixels are actually different colors.

By John Byne (not verified) on 06 Sep 2013 #permalink

Actually they *are* the same color. You can use a simple utility that will tell you the color of a specific pixel. I ran the utility just to check, and the two tiles you speak of are actually *the same* color. This WOULD be true if it was a physical object. Our minds will make us think they are different colors, when in reality, they are the same. In the images you have above, the pixels are actually *the same* color.

They ought to be different colours, though, if they were the same basic colour. Just like the white, blue, green and yellow.

All of those are different colours. The only one that's the same is the black.

You get a similar white balance error when you watch your TV. The black seems a HELL of a lot darker than the blue-grey black or the brown-green black of the TV when it's off, but when it's off, that's as black as it gets.

Because the browns should be different colours BECAUSE ONE IS IN THE SHADE, they don't represent the same colour the real thing would have.

A little like the Australian Aborigine pictures where the round pond is drawn round: just because perspective makes it look oval doesn't change the shape of the round pond.

The pixels are the same colour, but one is *representing* a different colour. It's not the *same* yellow as the other yellow blocks.

PS try squinting at the picture and look at the two brown tiles in the bottom half of the pic, the one on the checked pattern and the one on the cube.

Squinting helps bring them back into correct white balance.

John, they are the same colour. You will see tiny variations using your colour sampling tool because there are variations in colour across each tile. Many of these will be too small for the eye to distinguish.

Why is this? It may be to give the tile a 3d look, so it is shaded and/or it is because this pic has been floating around for years and due to resizing and compression, what once was a single solid area of colour is now a mosaic of very similar colours.

The bottom line is, to all intents and purposes, these squares are the same colour (or the same very small, restricted palette of colours if you're pedantic).

By Graphics Nerd (not verified) on 08 Sep 2013 #permalink