CSRRR is campaigning for roadside rescue and recovery operators to be able to use prominent red lights while attending accidents and breakdowns. At present, recovery operators are only permitted to be fitted and use amber warning beacons while attending incidents.
Due to a scientific phenomenon called the Rayleigh effect, the quality of red light waves are such that red can be seen from further away, hence why it is used by these other services.
There is a further effect though, because the colour red elicits a more serious reaction – whether consciously or subconsciously – in minds of road users approaching a hazard. Red is seen to signify a more serious incident than amber lights, and so road users take more caution accordingly.