George Moncur’s 82nd-minute winner helped the U’s get the vital victory they needed to stay up and beat the Lilywhites, who needed to win to go up automatically and now have to settle for a place in the play-offs.
Colchester boss Humes, who saw Chris Porter miss a 58th-minute penalty, said: “It’s a great achievement for the football club.
“Credit to the players out there, because they were absolutely brilliant. It was a tough game and they’re a good team but we stuck at it.
“It was a cagey game with not a lot of clear-cut chances. We didn’t go out to just stop them playing; we actually wanted to counter-attack and try and use our assets.
“But it was difficult, because they’re playing against experienced players. We kept going and going and kept doing what we believe in.
“Ultimately we got success from it. I was quite surprised when we got a penalty and whether it knocked them or gathered them together again, we don’t know.
“But George Moncur showed a little bit of quality at the end – he’s done it a few times this season and has been in the right place at the right time and that bit of quality.”
Simon Grayson admitted suffering defeat at Colchester was probably his lowest point as a manager.
The Preston boss said: “We had the opportunity to get promoted automatically on the last day of the season and hopefully it was going to be a good day for us.
“What I need to do is pick myself up and the rest of the players and I will do.
“I’m a strong character, I’ve suffered disappointment as a player and a manager.
“When you suffer disappointing days you have to make sure you bounce back very, very quickly.
“I’ll dust myself down and we’ll go again. There’s a big prize at stake for us still to get promoted.
“Everybody will question our record but records are there to be broken.
“Unfortunately we have to go into the play-offs but we will embrace it and be confident because we have a good group.
“You don’t finish with a number of points and a number of goals that we have without being a good team.”