A large U.S. health records study suggests that difficulty seeing blood in urine may put color-blind patients at higher risk.

People who are colorblind may be missing a life-saving warning sign of bladder cancer. Analysis of the electronic health ...

Anyone with normal color vision agrees that blood is roughly the same color as strawberries, cardinals and the planet Mars. That is, they're all red. But could it be that what you call "red" is ...