This is a proof of concept for an indicator to switch between Ambiance and Suru Dark theme.
This is based from the amazing work of Brian Douglass for Indicator Weather Thank you Brian!
It modifies the theme in the config file "/home/phablet/.config/lomiri-ui-toolkit/theme.ini"
Enabling Dark Mode from the indicator will switch to the theme "Suru Dark". Disabling it will revert back to "Ambiance". There is also an option to switch the theme automatically based on the time.
You can use clickable to compile.