For this puzzle I took 7 squares and coloured them using the ROYGBIV RGB values for Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Then I used the Dichromacy plug-in in ImageJ to simulate how these colors would be seen by a viewer with Deuteranopia (the more common form of color vision deficiency). I then shuffled the squares in random order on a square canvas, and numbered them 1-7 in clockwise order.
Puzzle: can you pair the squares numbered 1 through 7 with the colors R though V? I will give away the obvious one, which is the yellow (brightest):
1=Y 2=? 3=? 4=? 5=? 6=? 7=?
Cannot do it? For the solution just hover over the image with your mouse. If you like the animation and would like to use it on your blog, twitter, Facebook, you can download the animated GIF files, with numbers, and without numbers. Please be kind enough to link it back to this post.