Military vehicle licence of troops stationed in Hong Kong. Common license plate colors are blue, yellow, white, black and green, among which blue is the license plate of ordinary small cars, yellow is the license plate of large cars or agricultural vehicles, white is the license plate of special cars or police cars, black is the license plate of foreign-funded enterprises, and green is the license plate of special cars of armed police. Military vehicle number plate is the symbol of military vehicle, and its main function is to identify the unit to which the vehicle belongs and perform tasks.