It's not that simple.
Once you exceed 6000k, you lose light output. The color will vary from blue to purple depending on bulb brands, type of car, type of headlight, etc. etc.
No offense to anyone, but having seen 4100k, 4300k, 5000k, 6000k, 7000k and 8000k, I have to say that 6000k or higher is just
See pictures here
The last pic is 4300k vs 7000k. Look at the ground in front of the car. That's not a "hint" of purple. Having ridden in that car, the light output was complete trash and borderline dangerous.
When you take pics, be sure to take some of the headlights against a white garage door or wall.
