What does "color added" mean on a label for salmon at the grocery store?

“Color added” on a label for salmon and salmon products means that the salmon were given a feed which contains a pigment called astaxanthin. When the feed is digested, the astaxanthin is absorbed into the fish’s flesh giving the fillets or steaks a reddish or ‘salmon’ color. Astaxanthin is pigment occurring in nature that gives flamingos their pink coloration. It also turns cooked shrimp and crabs an orange-red color.  In the wild, salmon get astaxanthin through their diets, which consist …