Text background color of "Code and Syntax Highlighting" is difficult to see

In “Toggle Preview” mode, the text background color of the area set by “Code and Syntax Highlighting” is difficult to see. None of “Themes” has a color difference between the background color and the text background color of “Code and Syntax Highlighting”.

Hi Kazuhiko-san,

Thank you for the report but I don’t understand what you are talking about.
Please describe in detail as much as you can.
You can attach screenshots.