Meanwhile, back at the headlights, the one which is white LED at the front on the nearside of the train, has an identical one on the offside, but this isn't used. Not until, that is, it is at the back of the train and then they both shine in red LED.
I know it to be possible to change the colour of some LEDs by changing the amount current or voles, I forget which, you feed to them.
The nearside incandescent headlamp doesn't appear to be used in any configuration.
Also, why on The London Overground, are there buttons to close the doors?
There is no time during which these buttons are active.
That's a lot of buttons and (presumably) wiring on each train.
For what purpose?