Pistachio nuts, that is. Why are some pistachios red? Is it part of a conspiracy to stain our fingers so that there’s no denying it when someone yells, “Hey! Who ate all my pistachios?”

Long ago, all the pistachios sold in the U.S. were imported from Turkey and Iran. The processing facilities in the Middle East weren’t terribly modern, however, so once the nuts were brined and roasted, their normally tan shells often ended up stained and discolored. Savvy U.S. distributors realized that not only would a distinctive red dye disguise any surface imperfections, it would also make their nuts stand out in vending machines when they stood side-by-side with cashews and peanuts.

During the 1970s, California entered the pistachio game and was able to supply the nation with domestically grown nuts. For a time they sold them in their natural tan state, thanks to that whole Red Dye #2 brouhaha. But once a kindler, gentler red was developed, the California growers offered their nuts both ways: as Nature intended and with a slight blush for that nostalgia factor.