The Supreme Court on Monday allowed the Delhi Police to use red beacons atop its official vehicles and modified a previous directive of 2013. The court allowed the necessary modification while accepting a request by the Delhi Police. Unhappy with the Supreme Court order to use blue, white or multi-coloured lights instead of red, the Delhi Police had approached the court with a fresh plea to let it use what it described as “the best” colour for its operations as “red triggers the quickest response from public”. In its plea for modification of the December 2013 order, police cited the Rayleigh Theory in physics on scattering of light to assert that red has the maximum wavelength and, thus, has the maximum scattering of incident light. “Red light has maximum penetration even in low-visibility conditions such as fog, dust and night time. Blue light has the minimum wavelength, maximum scattering and least penetration,” it said. The plea said when the court delivered its order, the issue regarding the change in beacon colour was not deliberated upon and, hence, the scientific purpose behind the use of red beacons could not be pointed out. The application, which will come up for hearing later this month, said red has been traditionally used by police and Army as a “cautionary sign to alert people”. “Because of the historical use of red light as a cautionary sign, it is best for police and armed forces as it is also seen as a danger sign… It would be scientifically and historically appropriate to state that red light for police and army is appropriate,” the plea said. The Delhi Police said according to its research, many countries used red for emergency vehicles. It cited examples of the United States, Australia and Canada where the colour red was used by police. The application requested the court to modify its order under these circumstances and permit police and other organisations engaged in similar services to use red light. The court in its December 2013 verdict had said: “The men in uniform; operational agencies which require unhindered access to roads for performance of their duty; those engaged in emergency duties such as ambulance services, fire services, emergency maintenance etc.; and, police vehicles used as escorts or pilots or for law and order duties shall not be entitled to have red light but lights of other colours, eg, blue, white, multi-coloured etc.” It had held that red beacon light on vehicles can only be used by people listed as “high dignitaries”, that too only when they are on duty.
