The term Multi-layer CCD has been used to describe a CCD image sensor that captures true RGB using stacked CCD sensor layers.
This concept was the subject of a 1978 Kodak patent application (issued 1986), but did not result in a working image sensor.
The concept resurfaced as part of an April Fool's joke press release from dpreview.com. When the joke was released in 2000, a remarkably similar device was under development at Foveon—the Foveon X3 image sensor, which is multi-layered but is not a CCD. The Foveon sensor was announced on dpreview.com in 2002, with sample images.