I've replaced the bulb on my passenger side headlamp a while back and noticed that the coloring of the bulb was different from the one on the driver's side. I'm 100% sure that the passenger side bulb is 4300k, but the bulb is burning a yellowish-white (more on the white/clear side than yellow). I gave it some time to burn to see if the color would change to the purplish/bluish/white the oem bulbs have but no luck. With all that being said I was wondering if it had anything to do with the headlight harness. It's looking a bit beat up and is the cause of my concern. If anyone could let me know if it's the harness going bad that would be great.

 

what about the ballast? I would check the ballast before thinking is the harness.

 

Personally, I always replace the HID bulbs in pairs. You've already noted that there is a color (and likely light output) difference between new and old, not to mention that if one bulb recently burned out, then the other is likely to go soon as well.

 

^^ This, no matter how hard I've personally tried they are always slightly off. Replace both at the same time

 

I replaced both of mine at the same time and I have the same thing where one side is white and the other is bluish. I'm sure it's the ballasts, but I just ordered a set of JDM lights with a TRD HID kit, woo woo!!

 

damn baller! i wanted to do the same thing awhile back! but i didn't know that there was an hid kit for those housings. I'm assuming your're getting the black housing w/ the amber piece right? frickin rad bro!

 

It is not the ballast. It is the bulb. All HID bulbs experience a phenomenon called color shifting. Disclaimer: there are a handful of bulbs out there that are very resistant to this though. What happens is that the bulbs actually shift color with age. They shift towards a higher correlated color temperature (CCT). In other words, they get bluer as they get older. This is normal. Because of this, it is always recommended to change out HID bulbs in pairs (on cars). That way both bulbs should be the same color and shift in color with age together. Thus, both bulbs are the same color for the life of the bulb.

In commercial lighting, where HID (Metal Halide) fixtures are commonplace, in areas that having slightly different color lights would be detrimental (in other words, the same color of light is required throughout, for whatever reason), because of the color shifting of HIDs, group relamping is recommended. Group relamping means changing out all of the HID bulbs in that area all at one time, even if just one bulb out of the group went out. This mitigates the issue of having one or two light fixtures being a different color from the rest.

Now, for those with experience in commercial lighting, you know how hard it is to get two lights, regardless of light source, to be exactly the same color. It's really expensive to get two fixtures with light sources out of the same bin (or even a couple bins apart).