1. Preheat to 400*
2. Combine first 10 ingredients in a large bowl. Add salmon, turning to coat. Cover and let stand 15 minutes. Remove salmon from bowl, reserving marinade. Place salmon, skin side down, in a 9x13 baking dish coated with cooking spray.
3. Cut lemon in half lenthwise; cut 1 half into 1/8" thick slices. Reserve remaining half for another use. Add lemon slices, red & green peppers, 2 T water and tomato slices to marinade. Stir gently to coat. Arrange lemon mixture in an even layer over the salmon; cover with foil. Bake at 400* for 20 minutes or until the fish flakes easily with fork.
4. Place 1 fillet on each of 4 plates. top each serving with about 1/2 c. lemon mixture, and drizzle each serving with about 2 1/2 tablespoons of pan juices.