Tetrachromacy is real but vanishingly rare. However, I've read before that women have more bars and cones in their eyes than men & therefore better color reception, without being tetrachromatic.
I suspected my wife was a tetrachromat when we started debating what color something was. There are the "standard" arguments about is that blue or green or is that red or purple. But these were around yellow. Where she clearly saw two different yellows I could not distinguish them. She is unwilling to get the genetic test though, no matter how much I encourage her.