'Edit current scheme.'

def edit_scheme(self):

    dlg = self.scheme_editor_dialog
    dlg.set_scheme(self.current_scheme)
    if dlg.exec_():
        temporal_color_scheme = dlg.get_edited_color_scheme()
        for key in temporal_color_scheme:
            option = 'temp/{0}'.format(key)
            value = temporal_color_scheme[key]
            self.set_option(option, value)
        self.update_preview(scheme_name='temp')
