ACeP is the multi-dye tech. Basically, there are two ways of getting color one-ink: you either get a normal monochromatic e-ink screen and place a stained-glass

ACeP is the multi-dye tech. Basically, there are two ways of getting color one-ink: you either get a normal monochromatic e-ink screen and place a stained-glass checkerboard over it (which sucks, and is called CFA/Color Filter Array), or you make it so every pixel has black dye, red dye, yellow dye, purple dye, etc. CFA tech is what E-ink's "Kaleido" line uses, whereas ACeP is used in the "Gallery" line. Gallery Plus means, IIRC, they have 7 different dyes in each pixel (and takes 10ish(?) seconds to refresh, with the latest model). There's also the Gallery 3, which is an 8" screen that has ~4 dyes and can actually update the screen in a reasonable timeframe for interactive use.