In 1959 architect Neville Conder was commissioned to design a new box. The K7 design went no further than the prototype stage. K8 was introduced in 1968 designed by Bruce Martin. It was used primarily for new sites; around 11000 were installed, replacing earlier models only when they needed relocating or had been damaged beyond repair. The K8 retained a red colour scheme, but it was a different shade of red: a slightly brighter "Poppy Red", which went on to be the standard colour across all kiosks.