I'm thinking, because to me sorting is a matter of brightness or vivid color in descending order from the ends to center in this case.. that one could likely do it in monotone as effectively so I am not sure if calibration matters. I've also noticed that if the colors aren't arranged properly the bottom line or edge where each box rests looks jagged as if the box out of place is tipped a little to the right or left and not sitting flat. My eyes see the inconsistency in tone graduation. When in order it is a smooth straight line.