From upvoted:
Kimberly Jameson, a University of California, Irvine scientist who studied Antico, wrote that human tetrachromacy may be evolutionary advantageous … “Color deficient doctors may miss symptoms because of an inability to perceive the color of disease,” explains Jameson.

For the full story, please visit https://upvoted.com/2015/12/04/whats-a-tetrachromat-meet-a-person-who-sees-100-million-colors/.