Came here to link to this thread. Also make sure to check out the color e-ink displays by Clearink that the top comment mentions. They are quite impressive. (Unfortunately, I recently heard from the people behind the Supernote tablet that those displays by Clearink are very low in contrast and therefore require lots of ambient light. There goes the dream of color e-ink displays…)
https://news.ycombinator.com/item?id=26143779
Some of the early parents have expired but there are a lot of them…