Old Man,

Hatchery fish do spawn, just not successfully.

Buck,

The meat is white because the fish has used up most of its stored energy. The longer a steelie stays away from the ocean, the whiter the meat becomes.

Sniggler,

Don't know the particulars, but the red color to the flesh of salmon/steelhead comes from certain crustaceans they eat in the ocean. They actually dye farm-raised salmon to simulate real salmon meat because the farm raised fish eat pellets. There may be certain individual fish that do not eat a particular food source. I remember a smallmouth bass I used for a fish ecology project in college. This bass wouldn't eat the minnows I bought to feed my bass. Had to seine crayfish to get that one bass to eat!