Recently, it seems like food dye is making a comeback in a big way, and not just one dye—all of them. Rainbow colored bagels, grilled cheeses, pizzas, and even lattes have circulated the internet as the latest food trend. Is it just harmless novelty, or is there more to these culinary monstrosities?
Studies show that color not only plays an important role in how we taste, but can itself suggest flavors to our brains that aren’t necessarily there. Culture has a lot to do with which flavors we gravitate toward: People in most regions largely associate black with bitterness; green suggests sourness in the US and sweetness in India. “More often than not, we taste what we see,” Charles Spence, a professor of experimental psychology at Oxford, told Gizmodo over email.
Each color suggests some flavor, and those combinations aren’t just culturally dependent—they’re also personally subjective, as shown by a 2008 study on orange Smarties. Color cues and assumptions about color/flavor associations are separate but equally strong in tricking your brain into inventing tastes out of thin air.
But what about foods that have every color, like the aforementioned latte? Spence was unaware of any research done specifically about rainbow-colored foods, but he proffered a guess: “If I combine colours that make me think of strawberry, orange and cherry, who knows? Perhaps you might get enhanced sweetness.”
Color variety might also make us eat more. A 2014 review in Appetite found that more color keeps us from getting bored of eating the same food. The more frequently we are exposed to a food, the less appealing we will find it. That might explain why some of the most pedestrian foods are getting the rainbow treatment. For most people, a coffee, bagel, or slice of pizza is a daily or weekly food item that’s lost its luster through repetition.
Why is this taking off now? “I would say it is the natural result of [a] playful approach to deconstructing food,” Spence said. “Thinking about eye-appeal as essential part of enjoyment translated to mass market.” He also cited decreasing public concern about the potential harm of food dyes, thanks to the American consumer’s fondness for increasingly bizarre fast food. Novelty, and the sunk cost of waiting in line to get a novelty item, doesn’t hurt either.
Is rainbow food going to be around forever? No. It’s a fad like any other—and if it did become a fixture, it’d become as bland as the undyed stuff that it provides an alternative to. But in the meantime, take a bite and see what tastes different about it.