The Dukes (14-7, 4-4 Atlantic 10) have won four of their last five and are 10-1 at home. La Salle (5-13, 1-6) has lost five straight.
Colter made four 3-pointers and finished on 9-of-18 shooting. Micah Mason had 14 points and a career-best 10 assists, and Eric James chipped in 11 points and grabbed a career-high 15 rebounds for Duquesne.
Jordan Price scored 21 points to lead La Salle. Tony Washington had nine points and grabbed 12 rebounds.
Duquesne had a 40-37 lead early in the second half. L.G. Gill made a 3-pointer, sparking an 18-7 run to stretch their lead to 58-44, and the Dukes had a double-digit lead the rest of the way. Colter scored 10 points during the span.