Colombo's most significant competitive achievement was winning the 1974 Italian Formula Three Championship, succeeding Carlo Giorgio as champion and being succeeded in turn by Luciano Pavesi. His route to that title had begun in European Formula Two: in 1973 he raced for the Silvio Moser team in a Surtees TS10, and in 1974 he drove under the Vittorio Brambilla banner in a March 732 BMW — the same car and engine combination he would return to in successive forms through much of the decade.
Colombo contested European Formula Two from 1973 through 1980, an unusually sustained commitment to the championship. His first seasons with Trivellato (1975, March 752) and Delta Squadra (1976, March 752) produced a single championship point each. The breakthrough came in 1977 with AFMP Euroracing and a March 772 BMW: he placed seventh in the championship with 18 points, including a third-place finish at Mugello. That result remained his career high in the series.
The subsequent seasons brought steady but declining returns. With the Sanremo Racing team on a March 782 he finished eighth in 1978 (11 points) and thirteenth in 1979 (8 points). In 1980 Colombo's Sanremo campaign combined the March 782 with occasional outings in a Toleman TG280 Hart, leaving him tenth in the championship on 9 points. He also entered the British Formula One Championship in 1980 for Sanremo Racing on a March 782 BMW, though he scored no points in that series.
In 1978 Colombo made three attempts to qualify for Formula One World Championship rounds, all unsuccessful. Driving an ATS HS1 Ford DFV, he failed to qualify at the Belgian Grand Prix and again at the Spanish Grand Prix. A third attempt at the Italian Grand Prix in a Merzario A1 ended in pre-qualifying failure. None of the three entries produced a race start.
In 1980 Colombo attempted to establish himself as both driver and team manager through a new Formula One operation called Team Riviera, in partnership with Gianfranco Bielli. The team secured sponsorship from French sportswear brand Le Coq Sportif and acquired equipment from the defunct Kauhsen Formula 1 programme. A bespoke chassis was commissioned from designer Giorgio Valentini, formerly associated with the Merzario organisation, but funding ran out before the car could be assembled and the project never reached the track.
After stepping back from driving, Colombo channelled his energies into running the Sanremo Racing team through the 1980s, competing in European Formula Two and later the FIA F3000 Championship. The operation became an effective pathway for young Italian talent: among the drivers Colombo promoted were Gabriele Tarquini, Carlo Rossi, Guido Daccò, and Ivan Capelli, several of whom went on to Formula One careers.
| Season | Series | Entry | Result | |--------|--------|-------|--------| | 1973 | European F2 | Silvio Moser / Surtees TS10 | — | | 1974 | European F2 | Vittorio Brambilla / March 732 BMW | — | | 1974 | Italian F3 | — | Champion | | 1975 | European F2 | Trivellato / March 752 | 25th, 1 pt | | 1976 | European F2 | Delta Squadra / March 752 | 17th, 1 pt | | 1977 | European F2 | AFMP Euroracing / March 772 BMW | 7th, 18 pts | | 1978 | European F2 | Sanremo / March 782 | 8th, 11 pts | | 1978 | F1 World Championship | ATS HS1 / Merzario A1 | DNQ / DNPQ | | 1979 | European F2 | Sanremo / March 782 | 13th, 8 pts | | 1980 | European F2 | Sanremo / March 782 + Toleman TG280 Hart | 10th, 9 pts | | 1980 | British F1 Championship | Sanremo / March 782 BMW | NC, 0 pts |