Abstract: A light bulb, in particular one which has a light pipe in the form of a bar or tube, mounted to a light source. The light pipe has coloured lines extending along and within it. When illuminated by the light source, the light pipe acts as a means for dissipating light, providing the desirable effect of a traditional filament or incandescent bulb without the high temperatures and low energy efficiency associated with such a light source. Such a light bulb may also include a screw or bayonet fitting, allowing it to be retrofitted into existing lighting units, providing backwards compatibility with existing lighting installations.