 Many mini sets use standard 3 mm dome-shaped LEDs, and have a plastic cover over them to provide refraction, which is an important step in diffusing the unidirectional light they cast.These covers come in C5, C6, and C7 sizes (⅝, ¾, and ⅞-inch, or 16, 19, and 22 mm diameters, respectively) pointed "strawberries", G12 (12mm or almost ½-inch) globe "raspberries", and "M5" (5mm or -inch) pointed cylinders, equivalent to the T1¾ mini lights so common since the 1980s.For blue and green, these covers may have some fluorescence, leading to a lighter color.