@Nikola ,
if the border was only white not gray
Settings > Style Configurator > Language: Global Styles > Style: Fold Margin, change the Background Colour to white (or whatever non-gray color you prefer)
Plugins > Plugins Admin: in the Available tab, enable ☑ Python Script and Install. Notepad++ should restart after installing the plugin Plugins > Python Script > Scripts: in the resulting sub-menu, Ctrl+Click on the Startup (user)I wanted to try the trick with Pyton Script plugin but I would need step by step instructions
(if you normal-click, it will run the script; ctrl+click will edit the script – you want to edit it) It will open a file in Notepad++. At the end of that file, add the lineseditor1.setMarginLeft(30) editor2.setMarginLeft(30) and save that file. Plugins > Python Script > Configuration…. Change the Initialisation: drop-down to ATSTARTUP, and click OK Exit and restart Notepad++.
This should set wider margins. If it’s too wide or too narrow, use a smaller or larger number than 30 (bigger number means wider)
If it doesn’t work for you, show us your ? > Debug Info, and give us screenshots showing your edited startup.py open in Notepad++, and maybe with the Plugins > Python Script > Show Console showing, so we can see if there are any unexpected error messages