Health Secretary Robert F. Kennedy Jr. on Thursday announced the Food and Drug Administration was relaxing its enforcement of federal food additive regulations, making it easier for manufacturers to claim that they are not using artificial dyes in their products.

The F.D.A. has barred food makers from advertising that products contain “no artificial colors” unless they have no added dyes of any kind. But Mr. Kennedy and F.D.A. officials announced that the agency would no longer enforce that rule, so long as companies were not using petroleum-based dyes.

Mr. Kennedy and Dr. Martin Makary, who runs the F.D.A., said in a joint statement that the change would encourage food makers to use natural dyes instead of artificial dyes for products aimed at consumers who eschew “artificial” ingredients.

“We are making it easier for companies to move away from petroleum-based synthetic colors and adopt safer, naturally derived alternatives.” Mr. Kennedy said in a statement.

The agency also approved beetroot red, a new color option, as well as the expanded use of spirulina extract, an existing color additive derived from a type of algae. Those approvals bring to six the number of natural dyes that the agency has authorized since President Trump and Mr. Kennedy took office.

Mr. Kennedy’s effort to nudge food makers away from petroleum-based dyes is part of his broader effort to remake the American diet. The F.D.A. is considering a petition from Dr. David Kessler, who ran the agency in the 1990s, that has outlined a regulatory path by which the agency can rid the food supply of ultraprocessed foods — another high priority for Mr. Kennedy.