The 4.xx firmware version has included a new Developer Mode with some interesting things, one of its the Inverted Screen Mode without patching the Firmware.
To enable Developer Settings, simply type "devmodeon" (without the double quotes) in the search bar of your Kobo device.
Then go to Settings > Device information > Developer Options > View.
From there, check the box that says "On" in the "Invert Screen" line and exit the menu. Night mode will be activated.
To enable Developer Settings, simply type "devmodeon" (without the double quotes) in the search bar of your Kobo device.
Then go to Settings > Device information > Developer Options > View.
From there, check the box that says "On" in the "Invert Screen" line and exit the menu. Night mode will be activated.