Hi,

I've noticed that vehicle registration plates have different colours. I've worked out what a few of them indicate,  but there are some I haven't yet sussed. 

White background: the usual colour for most private vehicles. 
Blue background: vehicles registered for the carriage of passengers,  ie buses or taxis.
Red background: a vehicle that needs to be towed, that is not self propelled such as a trailer or caravan. 
Green background: dont know, could be an imported car. 
Orange backg