But Swindon could not make their man advantage tell as Nathan Byrne blazed the home side's best chance over the crossbar late on.
Severe weather played its part in a game of few clear-cut chances.
Fans were kept from entering the stadium until 7pm after a pitch inspection surprisingly gave the game the green light.
Colchester were happy to get on to the field after four consecutive postponements prior to their defeat at Port Vale on Tuesday.
Former Tottenham defender Byrne caused Colchester problems throughout and Michael Smith should have converted his cross after 17 minutes.
Swindon's victory hopes suffered a blow when striker Nile Ranger hobbled off with a hamstring injury before half-time.
- Sports & Recreation
- Nathan Byrne
- Louis Thompson
- Marcus Bean