We all know that some people see the world in a limited palette of hues due to color blindness. But what's the largest number of colors that we can possibly see?

In this video, Sci Show takes us on a whistle-stop tour of color vision, pointing out that normal folks can see about 1 million colors. But in fact there's a genetic mutation that allows a small number of people to register colors between red and green—allowing them to see a staggering 100 million colors. Watch this video to find out how that can happen. [Sci Show]