This is really not a PowerShell or VSCode issue, which is what we are here for. As this is a question about how do I configure VScode for X or Y.
So, this is really off-topic for StackOverflow and should be moved to SuperUser or StackExchange
Yet, you can always, create your own theme to use or crack open the theme file you are using and change it, if the author made to source code available of course, or use your settings (json files), PSReadline settings, etc... this is documented in the VSCode help files on the MS docs site.
Changing the Color Theme
https://vscode-docs.readthedocs.io/en/latest/customization/themes
How to edit default dark theme for Visual Studio Code?
With new versions of VSCode you don't need to hunt for the settings
file to customize the theme. Now you can customize your color theme
with the workbench.colorCustomizations and
editor.tokenColorCustomizations user settings.
Documentation on the matter can be found here.