Here's the thing, color shifting isn't an exact science. It depends on the maker and quality of the bulbs. I am curious to see where you got the information that 5000k would shift to 5500k?

But to answer the question, yes, shifting tend to go upwards in temperature, but obviously you're losing lumen throughout the gradual process. With that said, color shifting (besides the burn in period for CBIs) is a long process anyway.

And stock is 4300k.

 

Sorry for the confusion. In your post #13 your link describes the bulbs as 5000k. Later in your post #17 your post says after they burn in they are 5500k.

 

Yah, that is my mistake for the confusion.

CBI's true color is 5500K, but prior to that the color would be closer to 5000K. This is a CBI characteristic.

 

So my car's going on 8 years. If the original stock Xenons were 4300, do you think they are 4800 now since they are older? At this time I notice that one of them is slightly whiter than the other. Is one just wearing out faster?

 

The bulbs haven't been replaced in 8 years??

It's hard to guesstimate obviously without looking at it, but it most likely have went up in color. As for uneven wear, I don't even know how to answer that question. When was the last time you had two bulbs go out together?

 

I bought aftermarket 8000k HID bulbs because I was wanting more of a blue-ish light. Didn't get what I was looking for but it does have more of a hint of blue than the factory bulbs. I like it a lot actually. Definitely didn't want a purple look to them!