catfish, welcome to the forum!
You are correct; steelhead are an anadromous form of rainbow trout. Some other species of trout may run to the sea as smolts, eat and grow for a number of years, then return to the rivers where they were born, to spawn. Brookies (then called salters), brown trout in Europe, cutthroat trout-Hood Canal of Puget Sound-are examples.
I raise some trout in my pond. In years past when I was feeding commercial chows other than Optimal, my fish tasted like typical planter rainbows and were white fleshed and mushy. We disparagingly call them slimeys.
Since last fall I've been feeding Optimal Bluegill. The rainbows and tiger trout also have natural feeds, eg. various insects, crayfish, yellow perch and sunfish, etc. My fish on the present feed regimen have pink flesh and are rather tasty.
I normally will not eat trout unless they are from the high country lakes and streams out here in the west. Brook trout, high mountain lake cutthroats, and tigers from a specific lake in Utah all rate highly in my book.
Trout flesh will vary in color from white through pink to shades of orange. The texture will vary from mushy to relatively firm to almost flakey. Taste can be all over the place. Water quality, including temperature, and what the fish are eating contribute to flesh color, texture, and taste. I've always believed that fish feeding on crustaceans, such as wbuffetjr's scuds, will have the most colored flesh and the best taste. Brookies and goldens from high altitude waters with lots of these "fresh-water shrimp", as they're known out here, can have meat the color of sockeye salmon. They taste like the trout they are, ie, rare jewels from the high mountains.
Kokanee salmon, landlocked sockeyes, that we catch from a local reservoir, taste like salmon. The trout from the same lake, even though some are pink-fleshed, do not; they taste like mediocre trout.
The few wild caught, Pacific ocean steelhead I've eaten were incredibly delicious, but not salmon flavored.
