In a small bowl, mix paprika, cayenne pepper, onion powder, salt, white pepper, black pepper, thyme, basil and oregano.
Brush salmon fillets on both sides with half of the butter, and sprinkle evenly with the spice mixture. Drizzle one side of each fillet with remaining butter.
In a large, heavy frying pan over high heat, cook salmon, butter side down, until blackened, 2 to 5 minutes. Turn fillets, drizzle with remaining butter, and continue cooking until blackened and fish is easily flaked with a fork.