Preheat the oven to 450°F (200°C). Place the whole red, green and yellow peppers in the oven directly on the rack. Roast for about 15 minutes, turning if needed, until the skin is well scorched. Immediately place in a bowl covered with plastic wrap or in a paper bag, and allow to cool.
Remove the skins from the peppers by rubbing with your hands, and rinse under cold water. Cut in half, remove stem and seeds, then cut into strips.
Place peppers into a medium serving bowl, and stir in the garlic, vinegar, oil, basil, parsley, salt and pepper.