RGBW Sensor
An RGBW matrix (from Red, Green, Blue, White) is a CFA that includes "white" or transparent filter elements that allow the photodiode to respond to all colors of light; that is, some cells are "panchromatic", and more of the light is detected, rather than absorbed, compared to the Bayer matrix. Kodak announced several RGBW CFA patterns in 2007, all of which have the property that when the panchromatic cells are ignored, the remaining color filtered cells are arranged such that their data can be processed with a standard Bayer demosaicing algorithm.
Read more about this topic: Color Filter Array