Mac OS Mojave Terminal Resetting to Default Theme I've recently worked out how to change my terminal theme and set the new theme as default through the GUI menu: Terminal > Preferences > Profiles > Default. This works and sets the current session to that theme but after restarting Terminal the theme resets back to basic.

I've tried deleting all other themes and setting a specific one, and although this will work for the remainder of the session it does not work after restarting the app. 

I can't seem to find any specific help for this issue. Others have asked about setting a default or it not working on multiple windows/tabs, but that isn't the issue here. 

Is there a config file where I can change the theme manually?

Any suggestions will be very much welcomed!
Working on a 2017 MacBook Pro 15" (MacOS Mojave)
Setting the default profile does not mean that it will launch with the new window on startup. You need to set that in the General preference on startup, open: New window with profile: [YourProfile]


  is there a config file where I can change the theme manually?


Yes, you can edit the ~/Library/Preferences/com.apple.Terminal.plist in XCode (it's a binary plist file so while you can view the file in a text editor you don't want to save it as ASCII text).

You may actually want to delete this file though. After deleting it, when you launch Terminal it should be recreated with all the system defaults. That way they are there. You may have gone overboard with deleting everything.