content: #!/usr/bin/osascript
  
  tell application "Terminal"
  
      local allOpenedWindows
      local initialOpenedWindows
      local windowID
  
      set themeName to "Solarized Dark"
  
      (* Store the IDs of all the open terminal windows. *)
      set initialOpenedWindows to id of every window
  
      (* Open the custom theme so that it gets added to the list
         of available terminal themes (note: this will open two
         additional terminal windows). *)
      do shell script "open '" & themeName & ".terminal'"
  
      (* Wait a little bit to ensure that the custom theme is added. *)
      delay 1
  
      (* Set the custom theme as the default terminal theme. *)
      set default settings to settings set themeName
  
      (* Get the IDs of all the currently opened terminal windows. *)
      set allOpenedWindows to id of every window
  
      repeat with windowID in allOpenedWindows
  
          (* Close the additional windows that were opened in order
             to add the custom theme to the list of terminal themes. *)
          if initialOpenedWindows does not contain windowID then
              close (every window whose id is windowID)
  
          (* Change the theme for the initial opened terminal windows
             to remove the need to close them in order for the custom
             theme to be applied. *)
          else
              set current settings of tabs of (every window whose id is windowID) to settings set themeName
          end if
  
      end repeat
  
  end tell
  