The Bantams had suffered their first tough patch since Trueman took over with five games without a win.
But Mansfield loanee Andy Cook clinched the vital victory after Frank Nouble cancelled out Kian Scales’s opener.
“This business is all about winning,” stressed Trueman.
“On the psychological side of things it was important to get the win.
“We now have a platform to build on again. We’re delighted to get over the line. All the players and staff are delighted to get the three points.”
“When we had a poor run of results, we kept on doing the same things over and over again. This was a chance for us to improve and it was obviously just that final third and defending in both boxes where we’ve lacked lately.
“Here, we showed late on in the game that we can defend our box well when they’re putting pressure on us and also show quality in the final third.
“We are obviously delighted for Kian (Scales) – we know the qualities that he has got.”
The Bantams started brightly and the early pressure told as Scales opened the scoring in the 10th minute.
Influential Claydon Donaldson teed up Scales to masterfully curl home his first professional goal.
Jevani Brown squandered a glorious chance to level when he fired over after Courtney Senior had stormed through the Bantams’ backline.
Captain Harry Pell then inexplicably sliced wide from close range. But the hosts restored parity just before the break as Nouble converted Brown’s ball at the far post.
Towering forward Cook headed home Donaldson’s cross just before the hour mark.
Pell missed another great chance to get on the scoresheet.
Trueman’s troops almost doubled their advantage when Scales rifled against the crossbar with a stunning strike.
Jordan Stevens saw his effort clawed off the line deep in stoppage time after he had rounded Dean Gerken.
Colchester lie just four points above the relegation zone with eight games remaining.
Colchester United: Gerken; Clampin (Doherty 55), Smith, Eastman, Tchamadeu; Stevenson (Lapslie 62), Pell, Sarpong-Wiredu (Chilvers 83), Senior; Nouble, Brown (Cowan-Hall 83). Unused substitutes: George, Welch-Hayes, Folivi.
Bradford City: O’Donnell; Canavan, P.O’Connor, A.O’Connor; Wood, Evans, Scales (Stevens 90), Sutton, Cousin-Dawson (Watt 63); Cook (Rowe 79), Donaldson (Foulds 90). Unused substitutes: Hornby, Burrell, Shanks.
Referee: G Salisbury (Lancashire).