Last week, the FDA began to reconsider whether artificial food dyes impact our health. The nine dyes currently in use were approved in 1938, and officials have since attested to their safety. Nevertheless, the connection between artificial dyes and ADHD in children has been a matter of debate since the 1970s. The expert panel selected to review the matter reported that the scientific evidence does not merit placing warnings or restrictions on products using the dyes. But it also advised the FDA to pursue additional studies.

The battle over food coloring isn't new. While vegetable-based colorants have been used in food for thousands of years—ancient Egyptian chefs used saffron for yellow, the Romans used mollusks to impart purple hues and the red dye derived from cochineal insects were in use by the Middle Ages—the industrial revolution ushered in new technologies that allowed manufacturers to chemically alter the taste, smell and appearance of food. However, the metallic compounds used to create appetite-whetting hues were toxic—mercury, copper salts and arsenic among them. Farmers and some politicians railed against such practices, deriding them as attempts to bamboozle consumers into buying sub-par products. The controversy over how colorants could be used in foods came to a head in 1886 when margarine became a subject of national debate.

The oil-based spread originally called oleomargarine was a cheaper alternative to butter that originated in France and began to be manufactured in the United States in the mid-1870s. Although naturally white, dyes were added to give it a buttery shade—so between the lower price and the visual similarities, dairymen were not pleased to have margarine tromping on their turf. They decried the product as a fraudulent butter intended to deceive consumers. "You may take all the other colors of the rainbow," declared New Hampshire Senator Henry Blair, "but let butter have its pre-empted hue." The butter lobby's arguments were made without mind to the fact that butter's natural color varies depending on the diet of the cow—and that they used dyes to give it a consistent aesthetic.

Ultimately, the Margarine Act of 1886 was passed, placing a tax on margarine and requiring that manufacturers secure licenses to produce the product. Vermont, South Dakota and New Hampshire state legislatures all passed laws requiring margarine to be dyed bright pink—a visual declaration of the product's artificiality that was also sure to be perfectly unappetizing to prospective buyers. The Supreme Court later overturned these "pink laws" as unconstitutional.

Butter shortages during World War II allowed margarine to gain a strong foothold in American homes. It was sold in its pasty, white state along with a capsule of vegetable dye, which the home cook would have to mash in to turn it an appetizing yellow. In the postwar era, the laws restricting margarine's coloration began to lift and it gained in popularity. Even former first Lady Eleanor Roosevelt—who tried, unsuccessfully, to battle the butter lobby and provide tax breaks on margarine—appeared in a television commercial for the product. Ironically, in the early 2000s, Parkay tried to ride the trend of creating brightly-colored food products that catered to children and rolled out squeeze-bottles of—what else?—pink margarine.