Regulate and enforce colours of beacon lights

ISN'T the use of beacon lights and emergency siren systems regulated by the Road Transport Department? Can anyone use a beacon light and emergency siren in any vehicle and get special treatment on the roads? Aren’t they to be used in emergencies only?  

In Malaysia, ambulances – and now hearses – are installed with beacon lights. An ambulance usually uses the red or the red and blue beacon light, while a hearse uses amber beacon lights.