code: def delete_scheme(self):
          
          scheme_name = self.current_scheme
  
          answer = QMessageBox.warning(self, _("Warning"),
                                       _("Are you sure you want to delete "
                                         "this scheme?"),
                                       QMessageBox.Yes | QMessageBox.No)
          if answer == QMessageBox.Yes:
              # Put the combobox in Spyder by default, when deleting a scheme
              names = self.get_option('names')
              self.set_scheme('spyder')
              self.schemes_combobox.setCurrentIndex(names.index('spyder'))
              self.set_option('selected', 'spyder')
  
              # Delete from custom_names
              custom_names = self.get_option('custom_names', [])
              if scheme_name in custom_names:
                  custom_names.remove(scheme_name)
              self.set_option('custom_names', custom_names)
  
              # Delete config options
              for key in syntaxhighlighters.COLOR_SCHEME_KEYS:
                  option = "{0}/{1}".format(scheme_name, key)
                  CONF.remove_option(self.CONF_SECTION, option)
              CONF.remove_option(self.CONF_SECTION,
                                 "{0}/name".format(scheme_name))
  
              self.update_combobox()
              self.update_preview()
docs: Deletes the currently selected custom color scheme.