In a blender, or a food processor fitted with a metal blade, combine the yellow peppers and cucumbers, puree. Transfer to a large bowl. Add the onion and garlic to the blender or food processor and again puree. Combine with the yellow pepper mixture. Finally, place the yellow tomatoes in the blender or processor and puree to desired consistency; some like the puree smooth, while others prefer it chunky. Mix the tomatoes in with the other vegetables. Stir in the vinegar, the oil and the ice cubes if using. Season to taste with salt and pepper. Cover and chill.