@ElektroDragon, also note that there is a night-mode inverse-video hack that works on all Kobo models (you need the right version of the hack, though). See this thread:
https://www.mobileread.com/forums/sh...d.php?t=212162
And here for the latest version for current Kobos (Clara HD, and I believe the Forma):
https://github.com/gtalusan/kobo-nig...r/KoboRoot.tgz