A major theme of the Colle System is the ambition to play a well-timed e4, where the square is defended by the bishop on d3, the knight on d2 (following Nbd2), and possibly the rook on e1 (following 0-0 and Re1).

The Encyclopaedia of Chess Openings (ECO) identifies the Colle System as an uncommon continuation of the Queen's Pawn Game, assigning it the code D05.

[5] While acknowledging the system's "innocuous" reputation and its "slow and solid" plan of development,[4] Benjamin and Schiller recommended the Colle as a "good"[6] example of an unorthodox opening, as opposed to a "bad"[7] or "ugly"[8] one.

[10] George Koltanowski, in his book The Colle System, said it offered "solid development", combinations, and a decent endgame, giving White "good chances of not losing against a stronger player".

[13] Ding's compatriot Wei Yi also successfully used the Colle System in round 13 of the Tata Steel Chess Tournament 2024, defeating Vidit Gujrathi on route to the playoffs, with Wei Yi eventually winning the Masters section of the tournament.

[14] One variation of the Colle is the Colle–Zukertort System (named after Johannes Zukertort), characterised by developing the dark-squared bishop on b2.

A famous Colle System win featuring a slightly unusual Greek gift sacrifice is Colle–O'Hanlon, 1930.