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. 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.
[embeddoc url=”https://stemazing.org/wp-content/uploads/2018/10/Flag-and-RGB-Optical-Illusion.pdf” download=”all” viewer=”google” ]