Colombo was 1981 Italian junior champion. He reached in the following two years, respectively the semi-finals of the Challenger tournament in Brescia and was a professional tennis player in 1984. The following year, he won at the side of Paolo Canè his first doubles title on the ATP World Tour, the two were able to defend in 1986. In addition, Colombo won in Saint Vincent his first and only individual title by a final victory over Paul McNamee. In all, he won five doubles titles during his career. Its highest listing in the tennis world ranking he reached position 60 in the singles and in 1989 with position 68 in a double 1986.
His best individual result at a Grand Slam tournament was the respective reaching the second round at the U.S. Open in 1984. In doubles, he reached the third round of 1986 French Open.
Colombo denied 1987-1988 two singles and three doubles matches for the Italian Davis Cup team. His greatest success with the team was the quarter-finals of the World Group in 1988. During the 1-4 defeat against Yugoslavia was defeated alongside Paolo Canè against Goran Prpić and Slobodan Živojinović.