This should be addressed with the next update and using a different control for the file list (and other areas) that lend to better/more control over style/colors.
Unfortunately, AstroGrep doesn't support searching for directories directly. It is able to find files like you are trying, but it doesn't list out directories (when searching with no search text).
Installer - Add silent parameters for language and right click
Installer - Add silent parameters for language and right click
Currently the silent option to the installer just defaults to English and has no other options. You can change those via Tools->Options within AstroGrep. I'll create a feature request to be able to set those via parameters to the installer. Thanks for asking!
Search Option
You can already do this by using the file filter field and then having no text in the search text field.
Syntax Highlighting Colors Illegible in Dark Mode