Why Is Some Salmon Darker Than Other Salmon?

There’s a common notion that the darker salmon’s color is, the better it tastes. But is it true that deeply-colored salmon tastes better than salmon with lighter flesh? Why do different varieties of salmon look different anyway? What does it all mean?? The color of salmon differs according to the variety (Sockeye vs. King, for example) and whether it is wild or farmed. 

But there’s more to it than you might think, and not all of the hues are naturally occurring. If you’re a fan of this ubiquitous fish—the second most popular seafood in the United States, after shrimp—it’s time to understand the different colors of salmon. 

Wild Vs. Farmed Salmon

As a rule, Pacific salmon is wild and Atlantic salmon is farmed. It’s important to note, however, that “Atlantic” refers to the variety of salmon—the species known as Salmo salar—not just the region, because Atlantic salmon is now farmed all over the world. 

How does all this relate to color? Well, generally, wild salmon is darker in color than farmed salmon. 

Wild salmon get their pink color from the food they eat: shrimp or krill, which contain pigments called carotenoids. (It’s the same reason flamingos are pink!) The salmon eat the carotenoids and store them in their muscles. 

The color in farmed salmon, on the other hand, is not naturally occurring. Farmed salmon is generally lighter pink than the deeper reds of wild salmon, but their color is not naturally occurring. Farmers actually add a carotenoid-derived red pigment called astaxanthin to the salmon’s feed to turn them pink. 

What do farmed salmon eat, then, if not the crustaceans of their Pacific counterparts? A delicious diet of things like soybean meal or canola meal, with the carotenoid added in.

Farmed fish is also typically fattier and may contain wavy, white marbling, which adds to the overall lighter color. 

Salmon Color Can Vary by Species

Why are some varieties of Pacific salmon darker than others? It depends on how well they are able to metabolize the food they eat. According to the Alaska Department of Fish and Game—and they should know!—certain kinds of salmon break down the pigments, called carotenoids, better, which leads to a darker color. 

Other varieties, like a special kind of King salmon that’s actually white in color, cannot metabolize the pigments and store them. King or Chinook salmon can be any shade between dark red and this rare white variety that was once avoided but is now considered a delicacy. Sockeye and Coho salmon are typically the darkest, reddest color, and Pink salmon is, well, pinker.