Colombo uses an ancient language like modality (Sermo, 2002; Assassinio nella cattedrale, 1997; Ognuno, 1999),  like neoromanticism (Scrooge, 1996, broadcasted by RadioRAI Tre) , like contemporary (Il canto delle sibille, 2000 performed in San Marco in Milan and in Duomo of Siena).

He composed music for Tredici poesie by Roberto Mussapi (1997, broadcasted by RadioRAI Tre too), and some chamber works among which Eco di una lauda, (1996) for guitar.
He is the author of Iterum alte volat (1998) anthem of the Second Military School of Milan and of Un sogno di serie A (2005), anthem of Legnano Football Association.

With Aufstehen (1992), ballet set in a Nazi concentration camp, Colombo's interest in deportations and their social and psichological impact began. 

This interst brought him to compose Adenoid im Gral (2004) for an event connected to The Great Dictator by Charlie Chaplin, performed by Gottfried Wagner and Michael Chaplin in Schwerin (Germany).

Colombo studied ethnomusicology, and elaborated Milanese and Lombard songs.

He wrote essays (La musica mysteriosa, 1996, with Martin Mystère of Bonelli Editions) and gave radio lectures (L’opera svelata, 2002) about Opera broadcasted by Radio Classica.