The real X-Men are already among us. Or rather, the X-Women.

Scientists have learned that some women with an obscure genetic mutation appear to have superhuman color vision, capable of seeing a range of colors lost on the rest of us, reports the BBC.

Two different mutations on each of the X chromosomes must coexist for the ability to be expressed, so only women are lucky enough to possess it. When present, the mutations give these women — scientists call them "tetrachromats" — four cones in their eyes rather than the three that the rest of us have, unlocking a world of color.

A famous case is that of Concetta Antico, a tetrachromat artist who has shown through rigorous experimentation to be capable of seeing a range of color well beyond normal human levels. According to her website, she can potentially see 100 million different colors compared to the mere 1 million available to non-mutants.

“The little stones jump out at me with oranges, yellows, greens, blues and pinks,” she said. “I’m kind of shocked when I realize what other people aren’t seeing.”

Antico claims her ability gives her advantages, such as being able tell if a fruit is ripe just by looking at it. As an artist, she's able to pick out subtleties in color and contrast invisible to others. She is helping scientists to better understand the mysteries behind her kaleidoscopic ability, which researchers are learning is actually rarer than it should be.

For instance, scientists now know that merely possessing the mutation, and the resultant tetrachromat eyes, is not enough to give a person super vision. In fact, the mutation is surprisingly more common than once thought, especially among women of European descent, 47 percent of whom may have inherited it. But tests have shown that most of these women are not super rainbow seers.

The difference between someone like Antico and the average tetrachromat might be that Antico, being an artist, fostered her ability at a young age, while most others simply never exercise it.

“One possibility is that you need early training to capitalize on the signal,” explained Kimberly Jameson at the University of California, Irvine, who has tested Antico extensively.

In other words, if the ability is not fostered at a young age, the brain simply never wires up to take advantage of it, on the assumption that the added visual ability is not needed or simply not relevant, especially when an individual is socialized among normal seers who have no labels for all the extra colors.

Jameson and her team hope that by better understanding Antico's ability, they can aid other tetrachromats develop their inherent superpowers too.

“Now I have a whole new appreciation of what everybody else is not seeing,” Antico said. “It’s very shocking to me. Even when I found out I had tetrachromacy, I didn’t understand the extent of the differences in what I’m seeing and what regular folks are seeing.”