I have a logo at the top of my blog … it looks great on a white background! In dark mode, however, it looks really bad.
I turned to our old friend, CSS, to get me through this problem. First, I created and uploaded two versions of my logo: a light mode version and a dark mode version.
Now all I had to do was add the Custom CSS to overwrite the light mode logo hard coded into the HTML in the theme files with the dark mode logo.