There's evidence that a person's culture and upbringing can influence the range of sounds or shades of colors they can distinguish. So there might be many peop

There's evidence that a person's culture and upbringing can influence the range of sounds or shades of colors they can distinguish. So there might be many people with the potential for tetrachromancy, who just haven't had it trained-into-them by challenges as they learned vision and color perception. The researchers might want to take whatever performance tests they use to verify tetrchromancy, and make them into a progressively-harder game for children... to see if with early-enough practice the capability is more widespread.