By stimulating certain cones with extreme precision, scientists can help humans perceive a new color that defies all comparisons.

The human eye can see millions of colors — but no eyes have ever before beheld "Olo." Only five people on the planet — all from a team of researchers in California — have witnessed this brand new color.

Using an experimental technique called "Oz," researchers stimulated the human retina such that people saw a brand-new color.