Here's the info. I checked to be sure I wasn't running my own build - this is from the Fedora F34 Release repository. Attachment image.
This is after I have spent at least 30 minutes playing with some settings trying to get a readable UI. The Introduction, or Home screen - or whatever it is called - was very dark blue text on black background, and so was totally unreadable. The default font has been changed to "Source Code Pro" and font sizes increased to 11 (or possibly 12) . I'm pretty sure I have adjusted a few other things, but I can't remember.
Anyway, you can see that the text on the non-selected tabs is virtually unreadable. I haven't managed to make this any better.
Name : Code::Blocks
Version : 20.03-r11997
SDK Version : 2.0.0
Scintilla Version: 3.7.5
Author : The Code::Blocks Team
E-mail : info@codeblocks.org
Website :
http://www.codeblocks.orgwxWidgets Library (wxGTK port)
Version 3.0.5 (Unicode: wchar_t, debug level: 1),
compiled at May 6 2021 00:00:00
Runtime version of toolkit used is 3.24.
Compile-time GTK+ version is 3.24.29.