Dark Mode for Chrome, Firefox, Edge, and Opera is an extension/add-on that allows quick and easy switches between light and dark modes.
Dark Mode features a simple toolbar toggle button for switching it on and off. It also includes a white-list option that will permit you to exclude specific domains from dark mode. All that you need to do is add a domain(s) (comma separated) from the options page, and the selected websites are excluded from night mode. For ease-of-access, you additionally have the option to utilize the right-click context-menu to exclude desired websites as well.