Tech-On reports that Matsushita (Panasonic) showed off a new prototype color eBook reader with a 5.6″, 210 points-per-inch display at the NE Technology Summit 2005 event held in Tokyo yesterday. Given that their current grayscale Σ book uses a bistable display made by Kent Displays, I would hazard a guess that their prototype is using Kent’s new color ChLCD display (but that’s just a guess). Bistable displays like the ChLCD and eInk‘s microcapsule display (used in the Sony LIBRIé) take power to change an image but not to maintain it, so they’re incredibly low power for low-framerate applications like eBooks.