As pressure grows to get artificial colors out of the U.S. food supply, the shift may well start at Abby Tampow’s laboratory desk.

On an April afternoon, the scientist hovered over tiny dishes of red dye, each a slightly different ruby hue. Her task? To match the synthetic shade used for years in a commercial bottled raspberry vinaigrette — but by using only natural ingredients.

“With this red, it needs a little more orange,” Tampow said, mixing a slurry of purplish black carrot juice with a bit of beta-carotene, an orange-red color made from algae.

Tampow is part of the team at Sensient Technologies Corp., one of the world’s largest dyemakers, that is rushing to help the salad dressing manufacturer — along with thousands of other American businesses — meet demands to overhaul colors used to brighten products from cereals to sports drinks.

“Most of our customers have decided that this is finally the time when they’re going to make that switch to a natural color,” said Dave Gebhardt, Sensient’s senior technical director. He joined a recent tour of the Sensient Colors factory in a north St. Louis neighborhood.

Last week, U.S. health officials announced plans to persuade food companies to voluntarily eliminate petroleum-based artificial dyes by the end of 2026.

Health Secretary Robert F. Kennedy Jr. called them “poisonous compounds” that endanger children’s health and development, citing limited evidence of potential health risks.