Colazingari has won three gold medals at the U23 World Championships in the C1 team (2015) and C1 (2012, 2014) events. The two individual medals made him the first to win the title twice, an achievement met only by Nicolas Gestin in 2021. Roberto has also won two medals at the European Championships in the C1 team event with a bronze in 2017 and a silver in 2021 at Tacen and Ivrea, respectively. His best senior world championship results are 5th (C1: 2017, Pau) and 42nd (C2: 2011, Bratislava). Roberto formed part of an historic triple victory for Italy, winning gold in C1 at the 2019 Canoe Slalom World Cup in Tacen to accompany Stefanie Horn and Giovanni De Gennaro's gold medals in women's and men's K1.