The relevant text:
Electronic readers without backlit screens can’t beat the contrast and brightness of traditional ink and paper when it comes to colour.
Jason Heikenfeld of the University of Cincinnati, Ohio, and his colleagues, working with the Sun Chemical Corporation, also in Cincinnati, say that they have found a way to improve colour displays. Using inexpensive photolithographic techniques, the researchers made pixels with a reflective background and small wells containing water-dispersed pigments. Apply a voltage and pigment flows out of the well, coating the pixel (pictured left). Surface tension sucks the pigment back when voltage is removed; the switching is fast enough for video displays.
The researchers say their technique offers brightness, matt appearance and contrast that is superior to a related method that uses electric current to flip coloured oil droplets from beads to thin films across a pixel.
(It's just this highlight, no full-length article)