Kolonics started canoeing at the Budapesti Spartacus sport club, but soon moved to Csepel SC and remained at the club for his entire career. He first represented Hungary at the 1991 World Championships, and achieved a fifth and the sixth place in the C-4 events. At the 1992 Summer Olympics he achieved a fifth and the seventh place in the C-2 events with Attila Pálizs.