<i> Betsy Balsley is food editor of The Times. </i>

Remember when peppers came in only two colors, red or green? Now there is a rainbow of choices that come and go with the seasons--the brilliant golden bell-type, the vermilion pimiento, the rich purple bell with its startling green interior and several imports in chartreuse and yellow-gold tones. Try them, and you will find they add flavor to an ordinary dish and sophisticated color to any plate. ROASTED PEPPERS 6 assorted sweet peppers to cup extra virgin olive oil 1 large clove garlic, mashed 2 tablespoons minced fresh basil leaves or 2 teaspoons dried Salt, black pepper

Broil peppers about 5 inches from heat until charred on all sides. Remove from broiler and place in paper bag. Close bag tightly and set aside to let peppers steam. Remove peppers from bag, cut in halves lengthwise, peel, core and seed. Cut in long half-inch-wide strips and spread in bottom of shallow glass dish.

Combine olive oil, garlic and basil and pour over peppers. Turn to coat well, cover tightly with plastic or foil and chill 3 to 6 hours or overnight. Stir once or twice while marinating.

Let peppers stand at room temperature for 1 to 2 hours. Before serving, discard garlic and season to taste with salt and pepper. Makes 6 servings. FRENCH-FRIED PEPPERS 2 sweet peppers 1 egg Water Dry bread crumbs Oil for frying

Core and seed peppers. Cut in thin rings. Cook in boiling water 3 minutes, then drain well on paper towels. Beat egg with 1 tablespoon cold water. Dip pepper rings in egg, then in dry bread crumbs. Deep fry in oil heated to 375 degrees until crisp and golden brown. Drain on paper towels and serve hot. Makes 2 to 4 servings.