Colony 23 was a colony planet.
The Eleven and the Kandyman tried to take over its population by incorporating silk from the Psychic Spider's into confectionery products distributed throughout the world, forming a direct psychic link from its consumers to the Eleven, who planned to make them all submissive to him.
The plan was stopped by the Eighth Doctor, Liv Chenka and Helen Sinclair. (AUDIO: World of Damnation, Sweet Salvation)