Lindsay comes from a football family, the son of a Colorado State fullback and cousin of two former Oklahoma State football players. Two sisters played collegiate athletics, as well. Lindsay's high school career ended on a low note, though, as he tore his ACL and missed most of his senior season. Despite that, he still rushed for 4,587 yards and 44 touchdowns in his career. He was redshirted in 2013, but was healthy enough to be the Offensive Scout Player of the Year. In 12 games as a freshman reserve back, Lindsay was an all-around threat with the ball in his hands (79 attempts for 391 rushing yards; 14 catches for 118 receiving yards, 36 kick returns for 849 yards). The diminutive but tough-to-tackle Lindsay got his chance to start in 2015, beginning six of 13 games played and leading the Buffaloes with 653 yards on 140 carries (six touchdowns). He also contributed as a receiver, catching 26 passes for 211 yards and one score, but received fewer kick return attempts (7 for 154 yards). Lindsay became the main man on Colorado's offense in 2016, taking advantage of his speed, vision, and balance to garner second-team All-Pac-12 honors with 1,252 yards and 16 touchdowns rushing (244 carries) and 53 receptions for 493 yards and another score. Pac-12 coaches gave him honorable mention notice in 2017, despite increasing his rushing yardage (1,474), carries (301), and scoring 14 times on the ground in 12 starts. He also caught 23 passes for 247 yards and a touchdown.