The U.S. Supreme Court ruled that the juicemaker, POM Wonderful, can sue Coca-Cola for labeling one of its drinks “Pomegranate Blueberry” although it contains just a trace of those juices. (Karen Bleier/AFP/Getty Images)

It’s not nice to fool Justice Anthony M. Kennedy.

The justice said during oral arguments in April that he found the labeling of a Coca-Cola product called Pomegranate Blueberry Flavored Blend of Five Juices misleading, and Thursday he wrote for a unanimous Supreme Court that the company can be sued for it.

Kennedy said competitor Pom Wonderful, which also markets pomegranate juice, can pursue its claim that its rival engaged in false advertising.

The court’s opinion noted that “in truth,” the Coca-Cola product was made of “99.4% apple and grape juices, 0.3% pomegranate juice, 0.2% blueberry juice, and 0.1% raspberry juice.”

Coca-Cola and its subsidiary Minute Maid argued that it could not be sued for misleading consumers under a statute called the Lanham Act because its careful labeling met the requirements of the Federal Food, Drug and Cosmetic Act (FDCA).

Lower courts agreed with the company that Congress had given the Food and Drug Administration final say over the labeling.

But Kennedy said the two acts have coexisted since 1946 and are not contradictory but complementary.

“If Congress had concluded, in light of experience, that Lanham Act suits could interfere with the FDCA, it might well have enacted a provision addressing the issue during these 70 years,” Kennedy wrote.

Instead, “allowing Lanham Act suits takes advantage of synergies among multiple methods of regulation . . . to enhance the protection of competitors and consumers.”

David L. Ter Molen, a Chicago lawyer who writes the Food Identity Blog, said the decision “flipped on its head” conventional wisdom about food labeling.

“This is an area where companies thought they were on totally safe ground” if their labels met FDA approval under the FDCA, Ter Molen said.

He was surprised that the court delivered such a “clear-cut win” for Pom Wonderful and such a “clear-cut statement” about the ability of companies to bring suit.

Nevertheless, he said he did not foresee a flood of suits.

The court’s 8-to-0 ruling — Justice Stephen G. Breyer recused himself — did not address whether Pom’s allegations had merit; the court said only that the suit could go forward.

But Kennedy wrote that the product had a “minuscule amount of pomegranate and blueberry juices,” and described the juice blend’s label as displaying “pomegranate blueberry” in capital letters on two lines, with “flavored blend of 5 juices” in smaller type.

It was accompanied by “a vignette of blueberries, grapes, and raspberries in front of a halved pomegranate and a halved apple.”

If understated in the opinion for the court, Kennedy was outspoken during oral argument.

Coca-Cola’s attorney, Kathleen Sullivan, argued that the name and label met federal standards and said that “we don’t think that consumers are quite as unintelligent as Pom must think they are.”

Kennedy shot back: “Don’t make me feel bad, because I thought this was pomegranate juice.”

The case is Pom Wonderful v. Coca-Cola Co.