Ferrari's F1 158s raced in N.A.R.T. blue and white for two races at the end of the 1964 season. When the FIA refused to homologate the Ferrari 250 LM for international sports car racing, Enzo Ferrari returned his competition license and vowed to never race in Ferrari Red again. With the championship on the line, Ferrari's cars appeared in N.A.R.T. colors for the 1964 United States Grand Prix at Watkins Glen, and again at the 1964 Mexican Grand Prix. By the start of the 1965 season the dispute was resolved, and the cars were painted red once again.