They are used in book readers. Amazon Kindle Colorsoft, for example. Or I have android phone with such screen (though, not latest generation).
replyRather opposite: I never seen consumer products with two-layer displays.
Nope, that's my point, on your kindle, the screen is a Kaleido 3, which is a black&white+lcd layer: https://www.reddit.com/r/eink/comments/1i8e26x/seriously_how...
replyVs Spectra (the expensive screen): https://www.eink.com/upload/2023_11_14/3_20231114082849vy2as...
