Preheat the oven to 350 degrees F (175 degrees C).

Layer thinly sliced red peppers and tomatoes in the bottom of a baking dish. Arrange tilapia fillets on top.

Whisk water, oil, paprika, bouillon granules, cayenne, salt, and pepper together in a bowl; pour over tilapia, then sprinkle with parsley.

Cover the baking dish with aluminum foil and bake in the preheated oven until vegetables are tender and tilapia flakes easily with a fork and reaches an internal temperature of 145 degrees F (65 degrees C), about 30 minutes.