http://www.xrite.com/online-color-test-challenge Lower the number the better. I wish computer monitors can be used to test for Tetrachromacy. To learn more about Tetrachromacy go here: http://nymag.com/scienceofus/2015/02/what-like-see-a-hundred-million-colors.html I seriously doubt I am a tetrachromat. Please post your scores below. I thought this would be a fun test to do. I got a zero.