TARRYTOWN, N.Y. -- Mozzarella cheese at Panera restaurants won't be as glaringly white. Banana peppers in Subway sandwiches won't be the same exact shade of yellow. Trix cereal will have two fewer colours.
Food makers are purging their products of artificial dyes as people increasingly eschew anything in their food they don't feel is natural. But replicating the vivid colours Americans expect with ingredients like beets and carrots isn't always easy.
In fact, General Mills couldn't find good alternatives for the blue and green pieces in Trix, so the company is getting rid of those colours when the cereal is reformulated later this year. The red pieces -- which will be colored with radishes and strawberries -- will also look different.
"We haven't been able to get that same vibrant colour," said Kate Gallager, General Mills' cereal developer.
The shift away from artificial dyes represents the latest chapter for food coloring in the U.S., which has had a rocky history. As recently as 1950, the Food and Drug Administration said children became sick after eating an orange Halloween candy that contained a dye. The agency eventually whittled down its list of approved colour additives after finding several had caused "serious adverse effects."
Now, more companies say they are replacing artificial dyes with colours made from fruits, vegetables and spices, which are widely considered "natural," although the FDA doesn't classify them that way. But these present more challenges than artificial dyes.
In addition to costing more, colours from fruits and vegetables can be sensitive to heat and acidity. And since they're used in higher doses to achieve boldness, tweaks to other parts of recipes may be needed. Such adjustments can be tricky for companies that manufacture on massive scales.
Still, companies want to court people like Heather Thalwitzer, a 31-year-old homemaker in Melbourne, Florida. Thalwitzer avoids artificial colours because she wants her 6-year-old son to eat quality food and she said red dye has been linked to "mania."
She has tried alternatives like naturally colored sprinkles from Whole Foods, which her husband thinks taste like fish. But she can get along without such products. One year, she made cupcakes topped with a single blueberry for her son's birthday.
There are times when Thalwitzer makes exceptions, such as when her son is at a friend's party.
"I'll let him have the birthday cake," she said. "But I'll cringe."
THE EVOLUTION OF NATURAL
Part of the challenge with colours from natural sources is that the range of hues has been limited. Blues, for instance, weren't widely available the U.S. until 2013. That's when the FDA approved a petition by candy maker Mars Inc. to use spirulina extract as coloring in gum and candy.
The alga can now also be used in ice creams, drink mixes and other products.
"That was a big thing for us," said Stefan Hake, CEO of the U.S. division of natural colour maker GNT.
At the company's office in Tarrytown, N.Y., Hake demonstrated how to get blue from spirulina by pouring a liquefied version of it through a coffee filter to isolate the right colour components.
The approval of spirulina extract also opened up the world of greens, which can be made by mixing blue and yellow. It turns out plants like spinach brown in heat and aren't ideal for coloring.
Getting approval for a new colour source can take years, but it's one way companies can fill out their palette of natural hues. In coming weeks, an industry group plans to submit a petition to use the carthamus in safflower for yellow, according to colour maker Sensient Technologies.
"It's just one more that might be another crayon in the crayon box," said Steve Morris, Sensient's general manager of food colours for North America.
Sensient also developed a "deodorizing process" to remove flavours from ingredients. That allowed it to introduce an orange for beverages made from paprika.
Morris declined to detail the company's process. But since the ingredient is not "fundamentally changing the form," he said the ingredients are still within FDA guidelines of permissible colour sources.
Sensient said three-quarters of its new projects for clients in North America involve natural colours. Globally, its sales of colours -- natural and synthetic -- comes to about $300 million.
COLOURING INSIDE THE LINES
There are seven synthetic colours approved for broad use in foods. But these dyes can be mixed to create a wide range of colours. The colours are made by synthesizing raw materials from petroleum, according to the FDA.
Synthetic colours still dominate in the U.S., but some cite a study linking them to hyperactivity in children in calling for them to be phased out. Lisa Lefferts at the Center for Science in the Public Interest also says artificial colours can be used in deceptive ways.
"They mask the absence of ingredients," she said.
Tropicana's Twister in Cherry Berry Blast flavour, for instance, list apple and grape juice concentrates, but no cherries or berries. A synthetic colour gives it the appearance of having the latter fruits.
Of course, natural colours also are used to make foods more appealing and send visual signals about the ingredients they contain. Subway says it will stop using a synthetic dye to give its banana peppers, but will maintain their bright yellow look with turmeric.
Some say a switch to natural colour sources isn't yet possible because it might turn off customers, although they're looking into how to change.
"We have to deliver bold colours and flavours, or people will stop buying," said Will Papa, chief research and development officer at Hershey, which makes Jolly Ranchers, Twizzlers and Reese's.
Mars, which makes M&M's and Skittles, said it isn't yet using the spirulina extract it petitioned to have approved.
Not everyone thinks getting rid of artificial colours hinges on finding exact matches with natural alternatives. Panera is betting people won't mind that its mozzarella cheese might have a yellowish hue after the removal of titanium dioxide. For cookies with candy-coated chocolates, the natural colours it is testing are also duller.
Over time, people will get used to the more muted hues of foods with natural ingredients, said Tom Gumpel, Panera's head baker.
"You have to remove some of your expectations," he said.
