In general, sweet peppers are large, with thick, mild flavored flesh like the familiar green or red bell pepper. Besides these bell peppers, sweet peppers may be small and round like red cherry peppers or long and slender like Hungarian Wax or Lipstick peppers or heart shaped like pimento peppers. Many sweet bell peppers are sold at the green stage, well before they are ripe and they can be bitter at this stage. All peppers lose their green color when fully ripe and turn red, yellow, orange, yellow and even purple, depending on variety.