For all of you saying “What’s the Point?” this release is dedicated to you. The point is, you are not seeing what you think you are seeing. Your eyes are constantly adjusting to the context around them.
In the image at left, the two swatches are the exact same color. Now that I have told you that, you can see that. You probably even predicted there was some trick to this and guessed that the two swatches were the same shade of gray.
Let go of your pretense. When you let your eyes see on their own, the two swatches look different even though they are the exact same shade of gray.
They look different because of the color around them. We accommodate with our eyes. If we see a dark background, we make the lighter spot brighter, appearing lighter than it actually is. And just the same, on a light backround, the same gray appears darker than it actually is.
These exercises are not answers, these are tools to help you train your eyes. As you move your mouse along the array on the left of ten shades of gray, the background matches the swatch you choose. As well, the whole in the middle of the upright rectangles also matches the swatch you chose and thus the background.
Our perception of color is adjusting constantly.