Thank you so much. I got it working.
At first, I got confused – I went to the css in advanced options > head section, but I didn’t see the code there at first because the window was so narrow that it didn’t look like there was anything there except where it says, “<— Add your own css snippets between the style tags—>” but then I grabbed the lower right corner of the section and dragged it down revealing the code. So I cut and pasted it into the Global Custom CSS Rule Box. So everything is ok now.
So now I’m just waiting for the release of V5.0.4 to resolve the background color issue.