Just sharing my experience...
So I bought a set of 6000k bulbs after reco from some forum members (actually went with theRetrofitSource.com over a forum sponsor which I now regret). I bought the Morimoto 3Five 35w 6000's... well they arrived (quickly) and they were noticeably different colors... the one looked like a stock 4300 while the other looked like a 6000 (I matched it to my V-LED 6000k bulbs in the side marker).
At first it seemed reasonable... they wanted a picture of the difference and they would send me a new replacement (just one which is fine because the other bulb was still pretty new and would likely match).
After sending them the pictures they said they saw the difference but that I needed to send them another picture of me DESTROYING THE BAD BULB .
I explained that I can't drive the car around for a week at night with just one headlight and also wasn't really happy about having to remove the wheel and liner 2x (for uninstall and install of the new bulb when it arrives). I offered to send them the bad bulb (in tact) once I received the new one to replace it with. Also offered to send them a video of the bulb going through a wood chipper if it would please them, after I got the replacement of course.
My followup email I received asked me to send pictures of the color difference between the two (like I just did 2 emails ago) .
Thankfully I paid through paypal so I will have some backing should I need to dispute it.
I know 90% of you that have ordered through them have been thrilled but that was not my experience. Moral of the story is to go with the forum sponsors I guess. Never had a bad experience with any of them.
*EDIT* One note... I first contacted them when installing to notify them of the color difference and they told me to wait 2 weeks to see if they burned in the same color... I left my lights on every time I drove and there was no correction of color.