Just curious if anyone has first hand experience that HID bulbs get dimmer or duller with time? I bought a set of projectors used with an HID kit in it, and then recently added HID foglights which I bought new. The fog lights are the same temp, but appear to be way brighter than my used H1 bulbs.

The fogs are using a slim digital ballast, and the lows are on large-style ballasts. Not sure if that might have something to do with it either

 

From my understanding, they will change color/temp over time (going higher in the scale).

 

I guess that could be it. It seems more like an intensity difference than colour difference though. Ah well not a big deal. Maybe I'll just replace the kit when I have a few bucks laying around.