function onCommand( name ) {
		try {
			repl.deleteTheme( name );
		} catch ( err ) {
			repl._ostream.write( format( 'Error: %s\n', err.message ) );
			return;
		}
		log( repl, format( '\nSuccessfully deleted theme `%s`.', name ) );
	}
Deletes a syntax highlighting color theme.

@private
@param {string} name - theme name
@returns {void}