The Predators produced four goals in the second stanza and Hornqvist had the first and last of those to give Nashville a 4-2 lead.
Jason Arnott added a season-best four points, assisting on both of Hornqvist's goals.
Nashville had lost six of its previous seven games, but the Predators are still clinging to the seventh playoff spot in the Western Conference.
Pekka Rinne made 23 saves for the victory. Nashville downed Colorado for the third time in their four meetings this season.
Colorado has lost four of five following a six-game winning streak. Craig Anderson surrendered all five goals on 36 shots.