Well the bulbs seem to be working fine. They may appear brighter at first because of the huge amount of power they cause to ignite and the human eye sees blue as being brighter.

I have a 7000K HID kit and really wish i went with a lower temp for brighter lights (not that these arent bright just too blue). I originally ordered a 6000K kit from some HID website i heard good things about but receieved a 9000K violet HID kit instead. I complained but decided to keep them and when i put them in the one bulb did the same as yours and lit up dimly and then went out. It was indeed defective so i sent it back and they sent me a 7000K kit (not the original 6000k i wanted) so i complained but didnt feel like sending them back They are bright and all but you are probably better off with the 6Ks The difference between the 9000k's and the 7000k is huge in terms of light output. Heres a quick pic after warm up to compare to your color