Scientists are now developing tools, and even new colors, to test for tetrachromacy and experience what it feels like. But surprisingly, despite all having the genetic predisposition for the extra cone, most women did not have enhanced vision. But in someone with the mutation, the fourth cone might sit only a few nanometers away from one of the existing cones. “When your grandkids move to Mars, it won’t look red to them … if you’re living in a red world, it just looks grey,” he says. So far, instead of a color wheel, Ng has created a three-dimensional color sphere to capture the fourth cone’s extra dimension.