I'd be happy to pay an extra $100 for a good eInk color device. For example, if the new Sony 650 or 950 was available in a choice of monochrome or color and there was no degradation of the readability, I'd pay an extra $100 for the color version -- and I don't read comic books

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I think as publishers begin moving towards the digital book, they will be willing to provide illustrations and figures in color rather than b&w. Many of the b&w images in books today are color printed as b&w to save printing costs.
I also think having the color readers available will unleash book designers who will make use of the colors to make the books more enticing.
I can imagine a romance novel where we see a beating red heart (i.e., the word heart not a picture of a heart) when the heroine falls madly in love. I can also imagine a biography of John D. Rockefeller where the words describing his grab of monopoly money is shown in green. See -- a color reader could enhance the reading experience

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