Two of the largest grocery chains in the U.S. have agreed to place labels on their farm-raised salmon indicating the fish was artificially coloured pink.

Albertsons and Kroger still face lawsuits accusing them of deceiving the public.

Smith & Lowney, a Seattle law firm, filed three class action suits against Kroger, Safeway and Albertsons.

The flesh of farmed salmon is naturally grey and salmon are given special feed to alter their hue. This is also done in Canada.

To achieve the desired colour, the feed of farmed salmon is supplemented with an additive. The farmer can choose what shade of pink they want from a colour wheel called the "SalmoFan."

"While the supplements do not affect the taste or nutritional value of the fish, we are modifying the product labels to share this information with our customers," said Keith Neer for Kroger.

Paul Kampmeier of Smith & Lowney calls the decision a "victory for consumers."

Kampmeier says his firm still plans to follow through with the suit.

"Millions of consumers were damaged by the grocery stores' practice of failing to label," said Kampmeier.

Salmon farmers contend consumers connect a deep pink hue with freshness.