Why are UK car licence plates white on the front and yellow on the back?

Answer 1

It is down to the "Ministry of Silly Ideas" IN Brussells/Strasbourg

Current plates have black characters on reflective white PVC (for the front plate) or on reflective yellow PVC(for the rear plate). These are the colours used in the common EU plate format (though not all other EU states use the two background colours in this same way).

Older plates had white, grey or silver characters on a black background. This style of plate was phased out in 1972, and is now legal to be carried only on vehicles built prior to 1 January 1973.

Front number plates are 524mm x 112mm in size. Rear plates may be 524mm x 112mm (Standard), 285mm x 203mm (Square), 533mm x 152mm (large).

Answer 2

White plates on the front of the car reflect oncoming headlights, but to let other drivers know which way the car is facing yellow plates are on the back of the car. The idea of the yellow plate is that by law there are other reflectors on the rear of the car therefore the plate does not need to be seen as clearly as the white plate on the front of the car where there are no other reflectors.

Answer 3

Asked and answered a multitude of times here. It has to do with what light can be seen either as illuminated or reflected off a vehicle, and since the law requires red/amber from the rear, the rear plate is yellow, Bottom line, the law mandates it.

Answer 4

I gather the intention was to use reflective plates to enhance visibility (like reflectors), and ideally they'd have liked white both ends for maximum effect, but as the UK only allows red or amber at the rear they had to settle for the present colours (yellow being close to amber).