Public light buses are divided into two classes, visually distinguishable by the colour on the side and the roof of the vehicle. Their operations are regulated by a passenger service licence.

Green minibuses are licensed by Government to operate scheduled services on fixed routes to supplement other types of public transport by serving areas where bus services are not provided or constrained by road terrain.

By contrast, red minibuses operate without fixed schedules, routes or timetables, but they are not permitted on routes served by green minibuses. Red minibuses are free to set fares. Red minibuses tend to operate in the main transport corridors attempting to provide a more flexible and comfortable service than franchised buses.

There were 3,040 green minibuses and 1,310 red minibuses in Hong Kong as at May 2011.