| After LED jumped into the world of illumination, | | | | emergency vehicle lights are predominantly blue, |
| the idea of lighting has been redefined. Users have | | | | though countries like Germany, Sweden, Finland |
| the freedom today to have any light intensity | | | | etc., use forward looking red cop lights to convey |
| that they require and any type of color that they | | | | to a driver to stop. In Australia also cop lights are |
| need. The blacking out of a light has also been | | | | mainly blue. |
| made easy by the advent of LED because the | | | | Blue is used a lot in the cop lights of USA as well |
| technology is extremely suitable to making low | | | | but it is used to convey to another vehicle to |
| profile lights that are practically invisible. All these | | | | stop and pull over. Or it may just be used to |
| have revolutionized cop lights and its functionalities. | | | | signify arrival to a waiting crowd. Red and blue are |
| However cop lights colors have not undergone | | | | used in USA in other emergency vehicles like that |
| too many changes over the years. Mainly because | | | | of volunteer firefighters and EMTs either as full |
| the world over, a few standard colors have been | | | | warning lights or as courtesy lights. The rules on |
| used in emergency vehicles, color patterns have | | | | this vary substantially from state to state. Blue is |
| not changed because of the availability of more | | | | a color used in handheld cop lights especially during |
| colors. So the colors of cop lights continue to be | | | | night investigations because blue color has the |
| mainly red, blue, amber, and white. | | | | ability to highlight bloodstains. |
| Red is the predominant color found in cop lights in | | | | In cop lights amber is often used in parked |
| USA. It is a sign of emergency and is generally | | | | vehicles to caution or advise other vehicles that |
| accompanied by a siren. Other vehicles have to | | | | there is a problem in the area. Besides that, |
| give way and let the vehicle proceed when a | | | | amber is used in police vehicles in a set of traffic |
| police vehicle is coming with a red light. In | | | | control lights known as an arrow stick. The stick |
| countries like New Zealand, Japan, Canada, and | | | | is generally situated behind the main light bar as a |
| Hong Kong, red is a predominant color in cop lights | | | | group of 6 or 8 lights. The lights face backward |
| though in Hong Kong and Canada police use a lot | | | | and flash sequentially, directing other vehicles in |
| of blue as well. | | | | different directions. |
| As different from this, red finds limited use in cop | | | | White find limited use on police vehicles though it |
| lights in the UK. Emergency vehicle lights are | | | | is used a lot in handheld cop lights, adjusted to |
| mainly blue there with a combination of white | | | | differing intensities as required. Ultra violet lights |
| flashing headlights. Flashing red lights are | | | | are also used by police at a crime investigation |
| comparatively restricted in UK though rear-facing | | | | scene since these lights have the ability to highlight |
| red lights are sometimes used to indicate that a | | | | body discharges like sweat, saliva, urine etc. |
| vehicle is stationary. In the whole of Europe also | | | | |