Fresh fish will taste better than frozen; although if you do buy frozen, it thaws pretty quickly in cool water or even a pan of milk (helps with the stronger-flavored fish). We love salmon, grouper, trout, red snapper, and orange roughy, to name a few. Grouper, red snapper and orange roughy will look white even after they're cooked; although I think you may be referring to the method of cooking when you say you don't like white-looking fish. Grilling, blackening, pan-frying will change the look of the surface of the fish, but the flesh inside will remain white. Fish is done when it flakes apart easily with a fork. Generally, it's less than eight minutes, depending on the size of the cut.
I like to grill salmon (even on the George Foreman grill) with a little seasoning (salt, pepper, Tony Cachere's, lemon pepper, garlic salt -- whatever you like). It cooks quickly, so watch it closely so it doesn't dry out.
I press the fleshy side of a trout into seasoned bread crumbs (Panko). Heat a little olive oil in a skillet or shallow pan and cook the fish, breaded side down over med-low heat. Don't worry about the skin side - the skin peels off easily when the fish is done, and you can serve with the newly skinned side down so the pretty browned breaded side is showing. Trout generally has little bones, but they slide out easily after cooking. Sometimes I mix a little grated Parmesan in with the bread crumbs, or just sprinkle some on top after it's done.
I like grouper either grilled or pan-fried; red snapper and orange roughy pan-fried with onion slices and some chopped garlic. I don't like to use bread crumbs on these types of fish, but you can try it to see if you like it.
Another way I like to cook fish is to wrap a fillet (usually salmon, orange roughy, red snapper) in a sheet of parchment paper with some onion slices, garlic, peppers (whatever you like), drizzle a little olive oil or a few dots of butter on top of the fish, season with salt/pepper, wrap it up like a little present so the steam can't escape, and bake in the oven. Google some recipes for fish "en papillote" for more detailed directions. The fish will cook perfectly (although it will remain white with no crust), and will be seasoned with the vegetables you put in the package with it.
Good luck!