OFDarkmode is a script that updates the OmniFocus color palette between light and dark based off the macOS systems setting.
In combination with F.lux the system dark mode can be switch on at sunset via the "OS X Dark theme at sunset" color effect.
Download the script from the releases tab or build within Xcode.
While the script is running it is listening for updates to system dark mode. If you want this to happen consistently, add the script to login items.
Hope that you can find a use for it!
Matt
P.S - I'd love some feedback, open to feature requests too!