Universal Display has created a nice demo of their transparent OLED lighting panels - the Transparent Light Origami (TLO). It is made from 16 triangular glass PHOLED (Phosphorescent-OLEDs) panels that glow in either red, blue or green. When turned off, the panels are clear. Each panel is connected to the next via a friction hinge, so the structure can be folded and bent into a variety of shapes.
The design of the TLO was inspired by the observation that colors emitted by overlapping transparent PHOLED panels combine in an additive way, as is the case with overlapping PHOLED materials in an OLED panel. Red and green produces yellow, red and blue produces magenta, etc. All three colors overlapping produce white light. As illustrated by the TLO, when overlapping layers of red, green and blue PHOLED materials are sandwiched within a single panel, white light is emitted.