The Seasiders struck with the first real chance after 12 minutes as Nathan Delfouneso jinked past his man and delivered a pinpoint chip into the area, where Jamille Matt turned the ball home from three yards.
Blackpool goalkeeper Sam Slocombe denied Matthew Briggs with a sensational save to push the ball behind after 17 minutes, but the visitors did equalise from the resulting corner as Kurtis Guthrie prodded in from close range after a goalmouth scramble.
Somehow, Colchester failed to re-take the lead on the stroke of half-time as Slocombe produced a brilliant save from George Elokobi's close-range effort, before Guthrie headed against the bar from two yards.
Blackpool should have clinched the win 15 minutes from time, as Tom Aldred was found unmarked from a corner, but he headed wide from eight yards.
Colchester finished the game with 10 men, after substitute Sean Murray was shown a straight red for a bad tackle on Jim McAlister in injury time.
Report supplied by the Press Association
Match ends, Blackpool 1, Colchester United 1.
Second Half ends, Blackpool 1, Colchester United 1.
Foul by Jamille Matt (Blackpool).
Chris Porter (Colchester United) wins a free kick in the attacking half.
Attempt missed. Jamille Matt (Blackpool) header from the centre of the box is high and wide to the left.
Substitution, Blackpool. Eddie Nolan replaces Jim McAlister because of an injury.
Colin Daniel (Blackpool) is shown the yellow card.
Sean Murray (Colchester United) is shown the red card for violent conduct.
Jim McAlister (Blackpool) wins a free kick in the defensive half.
Foul by Sean Murray (Colchester United).
Delay in match Tom Eastman (Colchester United) because of an injury.
Attempt blocked. Colin Daniel (Blackpool) right footed shot from the right side of the box is blocked.
Attempt saved. Jim McAlister (Blackpool) right footed shot from outside the box is saved in the centre of the goal.
Attempt saved. Colin Daniel (Blackpool) right footed shot from outside the box is saved in the centre of the goal.
Corner,  Colchester United. Conceded by Clark Robertson.
Foul by Jamille Matt (Blackpool).
Tom Eastman (Colchester United) wins a free kick in the attacking half.
Attempt missed. Colin Daniel (Blackpool) right footed shot from the left side of the box is close, but misses to the left.
Substitution, Colchester United. Denny Johnstone replaces Kurtis Guthrie.
Attempt blocked. Jordan Flores (Blackpool) left footed shot from outside the box is blocked.
Substitution, Colchester United. Kane Vincent-Young replaces Richard Brindley.
Will Aimson (Blackpool) wins a free kick in the attacking half.
Foul by Kurtis Guthrie (Colchester United).
Attempt saved. Tom Aldred (Blackpool) header from the centre of the box is saved in the centre of the goal.
Matthew Briggs (Colchester United) is shown the yellow card for a bad foul.
Jim McAlister (Blackpool) wins a free kick in the defensive half.
Foul by Matthew Briggs (Colchester United).
Corner,  Colchester United. Conceded by Jim McAlister.
Attempt blocked. Owen Garvan (Colchester United) left footed shot from outside the box is blocked.
Attempt blocked. Sean Murray (Colchester United) right footed shot from the centre of the box is blocked.
Attempt missed. Tom Aldred (Blackpool) header from the centre of the box is close, but misses to the right.
Corner,  Blackpool. Conceded by Frankie Kent.
Attempt missed. Jim McAlister (Blackpool) header from the centre of the box misses to the left.
Corner,  Colchester United. Conceded by Andy Taylor.
Attempt blocked. Kurtis Guthrie (Colchester United) right footed shot from the centre of the box is blocked.
Tom Eastman (Colchester United) is shown the yellow card for a bad foul.
Jordan Flores (Blackpool) wins a free kick on the right wing.
Foul by Tom Eastman (Colchester United).
Andy Taylor (Blackpool) is shown the yellow card for a bad foul.
Foul by Andy Taylor (Blackpool).
Blackpool's winless run was extended to five games as they were held at home by fellow League Two play-off chasers Colchester.