colorblindness, n.Trivia

Women who are 'tetrachromatic', (meaning they have four cones instead of three) can experience 100 million colors (The rest of us 3-coned people can see 10 million colors)

Crocodiles are colour blind

colorblindness is tested with those dot pictures, but there is actually a reverse colorblindness test where only people who are colorblind can see the hidden image.

Bulls are actually colorblind. The matador's cape could be any color. It's the motion that attracts the bull's attention to charge, not the color red.