In Cuba number plates identify the driver not the vehicle and a range of colours and codes identify everything from your status in "the party" to your nationality and even how you make a living.
The colour coding of number plates is a system the powers that be have kept tabs on people for decades. Indeed it is a system copied from the USSR.
Government owned vehicles have dark grey number plates with white letters. The numbers signify where and when the vehicle can be driven and whether it can be used for personal as well as official duties.
Bosses at government owned companies get blue plates. They can only use their cars for getting to work and back.
In the USSR, Cuba's erstwhile backer, number plates were yellow and black, and the last two letters indicated the area where the vehicle was purchased, the first letter whether it was privately owned.
The USSR assigned numbers for diplomats number plates based the order of country recognised of the Russian Revolution. Britain was the first country and therefore the number plates begin with 001.
In Cuba, the first letter on the number plates show which province the car is from, "H" for Havana for example.
Army vehicles have red number plates, pale-green plates are for vehicles used by the Economic Ministry.
Purple number plates are for embassy staff, who have certain immunity to traffic laws, this also applies government ministers or heads of state organisations.
The first two digits on the number plates of diplomats indicate the diplomatic rank of the driver. For example, if you see a vehicle with the number plate xxx-003, that means the driver is the 3rd highest ranking diplomat from that particular embassy.