When fresh (even in the ocean) all chinook seem to smell metallic - like the taste of coins. The red spring I got 10 days ago on the Fraser smelled the same to me as the fresh springs I have caught in the Vedder. I agree that you don't want to keep anything that is turning dark, especially a white spring, but the fresh one's I have to admit I like. I first tried a fresh white spring when I caught a couple of chrome jacks on the Vedder. When they are fresh (chrome), the meat is pale pink, and turns white when you cook it. Of course, more of the fall fish have been turning out to be marble lately, and I did get a red spring last October, so who knows what you may catch.
Oh, and I can't say as I have had any trouble with white springs stinking up my smoker. The foulest fish I have ever caught was a chrome coho which had a 1" seal bite on its side. Lesson learned.