Depending upon your cut of salmon, the fish will likely be pink when it is done and some varieties like coho are naturally a very deep, almost ruby pink. The key to knowing salmon is done is that it is opaque and flakes easily. If it's a translucent-looking pink, it's likely not done. Testing with an instant read thermometer will remove any doubts. Remove the salmon at 135 degrees F to 140 degrees F for medium rare/medium and let rest.