They were taking part in the Bank Holiday Rochester Sweeps Festival in Kent, an event started in the 18th century to celebrate May Day.
Children in the Medway town had joined Morris dancers at the festival, which was immortalised by Charles Dickens in Sketches By Boz.
But a BBC crew from Blue Peter who were supposed to film the children refused after they saw their blackened faces.
Blue Peter editor Oliver Macfarlane said: "I was concerned that showing people with artificially blacked-up faces might be misunderstood and cause offence to some members of our audience.
"We did ask to film a group of other children dressed as Morris dancers but permission was refused. We are sorry to disappoint those children who expected to be filmed."
Tony Stalker, who had gone to watch the popular event, said: "This is political correctness gone mad.
"Everyone knows the black faces of the sweeps represents just the soot. Blue Peter should not read things into something that is just not there."
A spokeswoman for Rochester City Council, which organises the festival, said: "Blue Peter did express an interest in taking part in the Rochester Sweeps Festival but to our disappointment decided to cancel their visit."
She added: "Blue Peter's decision obviously disappointed not just the council, but also the groups continuing the tradition of the dancing sweeps and individuals who were prepared to give up their time to help with filming.
"The event was covered by other TV crews who had no reservations about coming."
The council said the children had taken their inspiration from contemporary pictures of 19th century sweeps and descriptions by Dickens, who lived in Rochester during his last years.
The event died out at the turn of the century but was revived by the City council in the 1980s as a tourist attraction.