He asked for no special consideration, he was always in good humor and a boon companion in company; but at the board he was a relentless fighter guided by a really ideal sense of duty and sportsmanship".

[2] The opening gained popularity, especially in the United States, through the efforts of Belgian-American International Master George Koltanowski, who remained faithful to it throughout his long career, and wrote several books on it.

The Colle System fell out of favor in high-level play as good defenses were found for Black.

However, because of its solid pawn structure, logical piece placement, and coherent strategic aims, the opening is often taught to novice players as a safe and dependable way to reach a playable middlegame.

Thus, the Colle System is frequently seen in amateur and scholastic tournaments, but is not common in professional play; however, it has been used in recent times by grandmasters Pia Cramling, Susan Polgar, Artur Yusupov, who prefers to play with b3 and a queenside fianchetto, a setup known as the Colle–Zukertort, and, most notably, Magnus Carlsen.