The Incredible Color Shift
"Hey, I just bought these Osram Xenarc D1S bulbs and they are YELLOW!" is, at times, a call I get from some of my customers. Usually, the customers are upset, understandably so, and they want to either replace, return or just ring my neck for the wrong recommendation. Understanding the nature of the call, I bring out the topic, "The Color Shifting of HID bulbs."
The color shift in HID bulbs is a normal phenomenon. The color temperature (Kelvin) rises as the HID bulbs get older, and the color output turns more bluish white. If you have HID bulbs that are over five years, first, congratulations. Once upon a time, your car probably had a set of 4,300K HID bulbs in your car. As the bulb ages, the output of the bulbs may have looked to you like it was pumping out 6,000 Kelvin! Then, one of your HID bulbs went out, ordered a replacement bulb from HID Concept. After installing it, you reach for your phone and said, "Hey, I just bought these Osram Xenarc D1S bulbs and they are YELLOW!"
When you install a brand new HID bulb, you may notice that the color is toward the yellow. If you install just one bulb against your old HID bulb, this difference can be more evident. This is another reason to replace the bulbs in pairs. For example, OEM 4300K Bulbs manufactured by Philips have been reported to have a more noticeable color shift than OEM 4300K Osram. OEM 4300K Bulbs manufactured by Philips has a color shift of approx 250K after 500 hours, which will bring it to up to 4550K. Again, the result would be different based on brand and model of the HID bulbs. Some Asian manufactured HID bulbs like Blesk are equipped with output stealing blue filters which may be the factor in not having a little or less color shift progress than OE bulbs.
So, next time you get your brand new bulbs from HID Concept, wait about 300~500 hours. The color shift should occur and the color should correct itself. The other alternative option is to purchase higher Kelvin HID bulbs (e.g. Dama Kanji HID bulbs, Philips White Vision or Osram Cool Blue Intense) which typically would give you an immediate result in color tone you may expect.