You may not know that SONY produces most of the sensors for most cel phones, such as iPhone 4S and 5S. Also they make a lot of the sensors for Nikon, as well as SONY cameras. IN the 16 MP chip, SONY is the main supplier for the world.
Now they have applied for a patent (JUlY 2013 report) for an 8 color chip for their upcoming designs. It has RGBCMYGW filter array.
Hey! They are returning to CMY for better color reproduction. That's the chip in the old Digilux 1, DMC-LC5 cameras that I love for their colors.
BTW, the RX100 has a white pixel added to its display (the display was a result of celPhone design.)
"The RX100 was the first camera to use Sony's 'Whitemagic' display technology first introduced on the company's Experia P smartphone. Whitemagic adds a fourth white pixel to the red, green and blue matrix hence the increase in resolution from 921,600 to 1,228,800 pixels."