Here are links to a few articles about the subject.
and a quote as to why
One industry official said the two chemicals that turn salmon's flesh pink -- canthaxanthin and astaxanthin -- are found in nature, as well, and aren't harmful in farm-raised fish.
"These are the same molecules that make wild salmon pink," said Kevin Bright, general manager of farms for Cypress Island Inc., one of the biggest farmed-salmon producers on the West Coast.
Fish farmers, the suit notes, artificially color their products by including the two chemicals in the food that the fish eat. The practice is done, the suit says, to produce more readily marketable fish flesh, because many consumers won't buy the fish if they don't have that traditional color.
Farmed fish, the suit says, would have gray flesh were it not for the artificial additives, because they don't get to eat other creatures like shrimp and krill containing the chemicals that give salmon their pinkish hue......
.....The two substances are added not only to salmon to create the pinkish color but also to hen eggs to turn the yolks bright yellow. Canthaxanthin also is used in tanning pills.
Both chemicals are from the same group of natural substances as beta-carotene. Both are antioxidants that give a reddish color to several animals, including lobsters and flamingos. In addition to enhancing salmon color, the chemicals help farm-raised salmon reproduce.
"There are all sorts of color enhancers in the foods we eat. It just makes it more appealing to the consumer," Bright said.
I just wanted to know your opinion on the ADDING of the color to the salmon (ps the word salmon has artifical color added to it to make it more appealing to you)