I've got a 06 sedan with factory hid's. Last night I noticed my passanger side bulb color has changed from the stock 4300k to 1200k or white to purple. The driver side if normal. What could have caused this? Thanks

 

Purple-ish Pink? Usually when a bulb changes color like that it means it's dying out. Just replace the bulb or better replace both since the drivers side might not last too long as well.

 

Swap bulbs first before replacement of bulbs or ballasts to see if it is the bulb it ballast.

 

Ok I'll give that a shot. Thanks

 

Bulbs color shift as they age and approach end-of-life.

I'd replace both bulbs. Honestly, to go 9 years on the OEm bulbs is pretty damn good. Expect 2-3 out of aftermarkets.

 

If he doesn't need to replace bulbs yet though because of Ballast failure, then why bother?

 

I got pulled over the other day for a hid bulb out. 10 years n 208k miles on originals. Just ordered some.

 

really easy way to test this theory out without spending any money. swap the bulbs or the ballasts.

the bulb discoloration can easily be ballast or bulb. generally when a ballast is on its way out, its much shorter on power. so the bulb cant heat up to proper temp (color)

when a bulb goes out, you have much less warning. and they normally fizzle out completely.
if the bulb is displaying an off color, whats changed in the dynamic. no technically no moving parts, so unless there is an air pocket with leaking gas, it will last another 15 minutes before it pops. or if a connection on the bulb is broken. the load is distributed over the other connections for a short period before overheating and breaking.

my bet is ballast. but you can check for free before wasting money on the bulb.

 

^^^^^

Electrical problems should typically be handled by professionals because throwing money at it solves nada.