The game was a back-and-forth affair throughout, with neither team able to build a substantial lead. Florida held a narrow 37-35 advantage at halftime.
In the second half, the Gators looked poised to pull away, but a 10-0 run by the Buffs tied the game at 55 with just over 10 minutes remaining.
With the game still tied with less than a minute to play, Florida's Tyree Appleby missed a shot from the free-throw line. After a scramble for the rebound, da Silva collected the ball and fired off the game-winning shot.
da Silva led the way for the Buffs with 21 points, including the decisive three-pointer. KJ Simpson added 18 points, while Evan Battey chipped in with 14 points.
The Gators, who entered the tournament as a No. 10 seed, were led by Anthony Duruji's 25 points. Myreon Jones added 14 points before fouling out with less than two minutes remaining in the game.
Florida coach Mike White was disappointed with the result but praised his team's effort. "We fought hard, but Colorado made one more play than we did at the end," he said.
With the victory, the Buffs advance to the second round of the NCAA Tournament, where they will face the No. 2-seeded Tennessee Volunteers on Sunday.
For Florida, the season ends with a 19-14 record. The Gators will now look to improve and make a deeper run in next year's tournament.
Read also: Barron Trump Towering Height Rivals NBA Legend LeBron James