The most accurate way to test the doneness of any type of meat is with a meat thermometer. Alternatively, check the salmon for doneness after 12 minutes of baking. As salmon bakes, it changes from bright pink (raw) to opaque pink. The outside of the fillet should be completely opaque, but the center should still be a bit translucent, but not raw. Cooked salmon will also easily flake with a fork along the muscle fibers.