Dark Mode is a browser add-on that helps you quickly turn the screen (browser) to dark at night time.
Toolbar button serves as an ON|OFF switch which enables you to easily and quickly turn the extension ON or OFF. If you do not like the current dark theme (dark theme #1), please visit the options page and choose a different theme from the 20 options available.
There is also a white-list feature which enables you to exclude a desired domain from dark mode. Simply add domain(s) to the designated area (comma separated) and the websites will be excluded from night mode.