Bias-cut zucchini into 1/2-inch slices. Cut tomatoes into 1/2-inch slices. Brush these vegetables on all sides with olive oil.
Grill zucchini and tomato slices on the rack of an uncovered grill directly over medium coals for 4 to 6 minutes, turning once. Remove from grill. Grill sweet peppers about 15 minutes or until skins are blistered and browned. Transfer peppers to a new brown paper bag; close bag and set aside for 5 to 10 minutes. Peel off skins. Cover and chill vegetables for at least 30 minutes.
For dressing, in a small bowl, combine vinegar, orange juice, and honey. Whisk or beat with a fork until well blended. Stir in basil and oregano. Drizzle some of the dressing over chilled vegetables. Store remaining dressing in the refrigerator for up to 2 weeks. Makes 6 to 8 side-dish servings.
If you like, substitute canned roasted red sweet peppers for the grilled fresh peppers. You'll find them in Italian food stores and most large supermarkets.