Darker Medium applies a customizable dark theme to *all* medium formatted stories. You can customize the header background, main accent color, highlight color and link styles separately from the option menu. No matter the domain, if a site is using Medium, it will get a dark theme; that is the main advantage over Stylus and Stylish.
Dark themes for Google, Facebook, and more
Darkness is a Chrome extension that provides dark themes for popular websites
f.lux for Philips Hue bulbs
Brilliance brings the outside world into your home through Philips Hue lights. Set your location, choose what kind of lighting you want: sunlight, weather-based, urban lighting, northern lights, and more, set a schedule to turn the lights on and off, then sit back and enjoy your lights without having to fiddle with an app or dimmers.