Organic Light-Emitting Diode
Any electroluminescence that is comprised of organic compounds. They do not require back light to function, and can be used in televisions, computer displays, and small portable devices. These sorts of light usually emit less light and therefore use less energy.
Below is a really cool example of OLED light put to use. Designed by Vadim Kibardin, This light-sensitive clock automatically shifts color, from black to white for day/night. It is energy efficient and compact, with no wires or central controller, the separate pieces can be stuck onto virtually any surface that has light exposure.Unfortunately, this design is only at the conceptual stage. But this would be a sleek, low key addition to your time kept space.