This dreadful technique lasted about 6 months, if that. The basic premise was if the customer wanted help from one of the Specialists, they would press a button in the centre of the screen and the desktop picture would change slightly from blue, to a kind of greeny blue. No buzzer or anything would go off, the Red Zone team were supposed to be vigilant of all machines on the shop floor, despite the fact they face in all directions and customer would have Safari over the top of the green screen. When they realised it wasn't working, they changed to to red, which freaked out the customers so much they would just walk away from the machine. Bollocks.