In a medium bowl combine chopped papaya, mangoes, peppers, cilantro and onion.
In a small bowl, whisk together vinegar, sugar, salt, pepper and olive oil. Pour mixture over the chopped items. Toss to coat evenly. Chill 30 minutes.
Just before serving, cut avocado in half, remove seed and cut in small dices. Add the avocado to salsa mixture and toss gently.
This salsa may be served on grilled tuna or salmon.