Production assistant George Gallaccio in Studio 4 at Television Centre for the recording of Planet of the Daleks in 1973.
In the hostile jungle of the planet Spiridon, the Doctor and a trio of Thals come upon an invisible mechanical device, immobilised by what Thal scientist Codal calls “light-wave sickness”. A circular depression in the ground is the only indicator of its presence – until Codal passes the Doctor a can of liquid colour. As black paint coats the device, a familiar form takes shape. A Dalek!
The Thals’ ‘liquid colour spray’ and the BBC’s Colour Separation Overlay reveal the threat in Episode One of Planet of the Daleks.