You can either print these out in color or just look at them on a screen to see an afterimage based on how your red, green, and blue color receptors work in your eye. Scroll completely to the bottom to find a document best used for on screen viewing.
What colors do you see? The side with the boxes has the primary colors of paints/pigments. You should see the primary colors of light as the afterimage. The side with the strangely colored United States flag, you should see the United States flag in red, white, and blue as the afterimage.
Print in color on white cardstock, double-sided and select “Flip along LONG-edge”. Then cut length wise to net two copies per page. This version with the white space makes it easier to use.
Print in color on white cardstock, double-sided and select “Flip along SHORT-edge”. Then cut in quarters to net four copies per page. This version nets you more copies but then a person has to find something white to look at to make the afterimage work.
Download the file below and use it in present mode to either project on a screen or view it on your monitor to experience the afterimage without needing to print it.