HID Color Temperature
If only everyone could have a fancy new luxury car with those blue-ish white lights that put normal Halogen bulbs to shame. Alas we are not created equal, so what is one to do when they put the hammer down and decide to upgrade to High-Intensity Discharge Headlamps(HIDs)? The first step is to decide what color temperature you wish to purchase. Read our other article, “What Are HID Lights”, for basic information about this amazing technology.
The visible light spectrum is divided up by a characteristic called Color Temperature. Color temp is defined by the temperature of an ideal black body radiator that radiates light equal to its surface temperature. A black body is an object that absorbs all light and emits light dependent on its surface temperature. To boil it down into simple terms, Color Temperature is the color code given to a particular light source based on how we perceive it with human eyes. This code is stated in units of absolute temperature, Kelvin (K). For example, the suns color temperature at midday is listed as 5780K (bright white), however this is not precise. You will see the suns color rated anywhere from 4300K to 6500K depending on the sources used and how much light the black body radiator could absorb during testing.
Many people believe that color temperature of an HID light is based on how bright it is (higher the K rating, brighter it gets), this is false. The higher the Kelvin temperature rating, the more blue/violet the light becomes and the less useable light output there is. Higher color temperatures are known as cool colors (5000K and up) and produce bluish white to violet light while lower color temperatures (5000K and down) are called warm colors and produce yellowish white to red. Below is a chart depicting most of the color temperatures available for HID lights.
|3000K||Yellow||Emits a yellow light. Often used in place of halogen fog lamps.|
|5000K||Pure White||Emits a pure white light. This is the color of choice for most car manufactures and can be found equipped on a wide range of vehicles. Used if you want the most light output and the best performance.|
|6000K||Crystal White||Emits a pure white light with a very subtle hint of blue, this is the most popular color choice for aftermarket HID installs.|
|8000K||Light Blue||Emits a more blue light than 6000K but is not defined as true blue because it has a hint of white.|
|10,000K||Blue||Emits a dark blue light output that is close to violet in the color spectrum. Visibility is significantly decreased.|
|12,000K||Violet||Emits a violet/purple light. This color has the least light output and should not be used for nighttime driving.|
The color of your HID light is also dependent on the type of lamp housing your vehicle has, be it reflector housing or projector housing. A reflector housing is the most common housing at this time and is designed for use with Halogen bulbs. Reflectors do not create a color shift of the HID light and will be uniformly the same color throughout. Installing HID lights in a reflector housing is not advised because they are not designed to handle the significantly brighter output of an HID bulb and will blind other drivers. The newer projector housings focus the light precisely and reduce glare for oncoming traffic. A 4300K white bulb appears blue or purple at certain angles because the projector lens bends the light around the cutoff points but leaves the road white.
This may seem like a lot to swallow but it is relatively simple. Factory HID systems use 4300K bulbs while most aftermarket systems use 6000K or 8000K bulbs. Going above 8000K or below 4300K decreases light output significantly and should only be used in show cars. Choose your color wisely and know that the higher the Kelvin color temperature the lower the light output and the more blue/purple the light will become.
Although Aftermarket HIDs greatly improve visibily they are only intended for OFF ROAD USE. They are not DOT approved and you can be ticketed for using them on public roads. Make sure to check local laws for further information.