[parkher]

Well, I put Note, Note 2 and Mimas (also black) next to each other and it is really difficult to see a difference.
Besides, there are various different contrast settings in them - Mimas even has a global contrast setting, and then, try to match various settings in reading apps. Good luck with their different native apps. As to Cool Reader, for some reason it does not recognize that Mimas has an e-ink screen. So there are even more settings to deal with - to get rid of textures, etc. So CR on Mimas therefore has a brightness control in its settings - you can make the background of the page darker and darker (it is not a frontlight control).
Furthermore, it seems that gamma values are very different when e-ink is recognized and when it is not. So when on Note 2 the value of 1.0 is good enough, Mimas requires a much higher value.
Anyway, the text on the screen is very similar on all three - it is possible to achieve a very similar result.
Of course, the frontlight on Note 2 and on Mimas are off.

Speaking of which, Note 2 has two separate sliders for white and yellow light, and two switches to switch them off completely, one by one.
Mimas has only one slider and a switch between day and night, so in the night mode only yellow light remains. And the global off switch, of course.
At least they both allow to switch that light off completely, unlike all the Kindles.
If I understand it correctly, you need to hack a Kindle in order to switch the light off completely.
I am really thinking about buying a Kindle myself - so that I can sue Amazon and get a lot of money from them.