This is a little KUAL extension that leverages the method
on this thread to allow a sort of fake night mode on non-Paperwhite Kindles (i.e. ones where night mode is not officially supported on the stock firmware).
As it uses fbdepth and fbink, it requires USBNet installed.
Caveats:
- I've tested this only on my KT4, I'm not really sure how it'll behave on other models - worse case scenario, if it breaks horribly, like the screen blanks out, freezes, or doesn't seem to respond to touches, you may need to force reboot your Kindle. Feedback on working devices are welcome!
- When in night mode, ghosting effects are much more pronounced; you'll either have to force a screen refresh very often (by touching the status bar, then back at the center of the book) or just leave page refresh turned on all the time (Settings > Reading Options > Page Refresh), as the screen refresh clears up the ghosting. YMMV, of course, that was just my experience with the KT4;
- The night mode setting doesn't survive a reboot.
To install, just drop the contents of the zip file inside the extensions folder on the internal storage.