Heat a pan and add paprika, cook 1 minute. Remove and set aside. In small saucepan over high heat, reduce orange juice to a syrup. Place paprika, reduced orange juice, vinegar and mustard in a blender and blend until smooth. With the motor running, slowly add oil until emulsified. Season with salt and pepper to taste.
Preheat grill. Brush fish with olive oil on both sides and season with salt and pepper to taste. Grill the fish for 10 to 12 minutes total. Remove and serve each person 1 whole fish drizzled with vinaigrette.