When you use the Google Chrome version 73 or higher, and the macOS Light Appearance is enabled. Your Google Chrome web browser user interface is still light. And when you enable the macOS appearance settings to Dark. All your finder windows and also your Chrome web browser is dark. And that is not good for all users. And if you want to get a Dark Mode on only your Light Appearance of your macOS. Yes, you can with this free and easy solution.
Solution macOS Catalina Chrome Dark Mode

- Install the Dark Theme for Google Chrome from the Chrome web store
Now you have a beautiful macOS Catalina Chrome Dark Mode only in your Chrome window, and not the Dark Appearance of your macOS.
This idea works also vice versa if you need a Light Chrome Theme for your Google Chrome web browser when your macOS is enabled on the Dark Appearance.

- Install the Light Theme for Google Chrome from the Chrome web store
As a result you have a beautiful macOS Catalina Chrome Light Mode only in your Chrome window, and the Dark Appearance in your complete macOS.
In conclusion, you get a dark experience that day and night when you browse on the internet with your Google Chrome web browser. And if you want to convert also all your websites, you can install the Turn Off the Lights Chrome extension.
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