Customizing FG/BG Colors and Font Size of Display Text/Results Windows

I'm working with the Execute Shell Script action and have "display results in window" selected. With Catalina Dark mode this yields a window with white text on a black background, but the font size is a bit small for these aging eyes. I'm looking to increase the font size, but everything I read about adjust font size & color seems to only apply to using the "Display Text in Window" action.

I tried using the "Display Text in Window" action by changing my macro to save the output of "Execute Shell Script" into a named clipboard and using the proper token in the text area -- which allows me to change the size and color of the test, but the background of the text area is white. Is there a way to change the text area window background?