Coat a 10-inch nonstick skillet with cooking spray; place over medium heat until hot. Add peppers and onions; cook 4 minutes, stirring occasionally.
Pour egg substitute into skillet; sprinkle with salt and pepper. Cook, without stirring, 2 to 3 minutes or until golden brown on bottom. Sprinkle with cheese. Loosen omelet with a spatula; fold in half. Cook 2 additional minutes or until egg mixture is set and cheese begins to melt. Cut omelet in half. Slide halves onto serving plates.