I am a web and email designer and all of my pages have to be designed for both light mode and dark mode. In Windows, I usually keep Microsoft Edge in Light Mode and Chrome in dark mode so that I can save the webpage and then refresh it in both browsers to test compatibility.
Is there a way to do this in MacOS? I have a MacBook Pro but I can't figure out a way to keep Safari in light mode, but Chrome in Dark mode. So annoying to have to go into the system preferences and change the appearance of the entire laptop when the apps should have their own appearance settings.
Unfortunately you are correct; Safari doesn't allow for the theme to be changed, and I'm not sure about Chrome. However, you can manually set Firefox to use a light or dark theme, if that helps.
Vivaldi is a Chromium based browser with lots of customizations including custom themes. Here is a screenshot showing just a portion of the theme options: