Kvaca, 19, is out of the HC Ceske Budejovice program in the Czech Republic. He played in 18 games with Ceske in the second-tier pro league last season and won a championship with the team. During the regular season, he had three shutouts and a .939 save percentage while leading the league with a goals-against average of 1.14.
The 6-foot-1, 174-pound netminder appeared in two contests in 2016-17 with the Budejovice under-20 squad, registering a 3.50 goals-against average and .908 save percentage.
Kvaca played four games with the Czech Republic's under-19 team at the 2016 World Junior A Challenge and was also a member of his country's squad at the 2017 IIHF World Junior Championship, but he did not appear in any contests.
Colorado received the 114th pick from the New York Rangers at last summer's draft in exchange for defenseman Nick Holden.