This is a great idea.
Wait... Yota, please patent it worldwide before certain fruit company claims it's their innovation, I'm not trolling or kidding...
Now, at any given moment are both of the screen active? If only 1 of the screen is active, can you seamlessly switch between the screens? It'll be great if I can play games and watch movie on the color side, and for everything else I'll do it on the e-ink. Someone else mentioned about color e-ink, move on to it in the future and we can see a new trend for smart phones. True innovations 😉