The Sky Blues booked their ticket into the Emirates FA Cup second round on Saturdays with their first away victory of the season.
Goals from midfielder Jordan Shipley and defender Sam McCallum earnt City the win and boss Mark Robins was pleased with the afternoon as a whole.
Robins said: “We worked really hard and played really well as a whole team.
“We have had a lot of injuries recently but all the boys played really well today.
“We have got a clean sheet away from home and our first win away from home which is long overdue.”
Robins included four central midfielders in his starting eleven and the manager was impressed with how the system paid off.
Robins said: “Shipley and Westbrooke ran off the ball really well and Walsh and Kelly were good too because they had to be brave when they took the ball and they controlled it really well.
“Our midfielders are clever, they are brave and will get on the ball which whilst they are all technically good.
“We had a lot of the ball and we used the ball really well by putting them in positions they didn’t want to be in by getting off the back of their midfield.”
City limited Colchester to very few chances during the game and Robins was impressed with the whole back line.
He said: “Fankaty Dabo and Sam McCallum were outstanding again.
“They had to be brave and know when to get forward while the three at the back, the centre halves, were really good.
“The goalkeeper was good, he organised things well and we did what we had to do.”
City went into the break two goals to the good and Robins was pleased with the positive opening to the game.
Robins said: “We dominated a lot of the ball but it just came a bit ragged towards the end of the first half and the second half was tough because we had used a lot of energy.
“They freshened things up and we tried to do the same, with Callum O’Hare and Josh Eccles coming on and we just kept going all the way to the end.
“Shipley also had a goal disallowed which was chalked off wrongly because I have seen it back and it was onside.
City will discover their second-round opponents in Monday nights draw and being in the hat was Robins’ top priority.
He said: “I have got to be pleased with the support, with the day and the whole thing.
“It was always going to be a tough challenge but we have overcome it and we are in the hat for the next round which is really good.”