High kelvin bulb ratings are a meme and unrealistic. Why anyone would willingly spend hard-earned money on making their eyes strain more than necessary is beyond reason. Sure, the colors blue and purple are pretty neat I suppose, but to buy lights to emit at those spectrums is retarded and completely useless. Personally I think 4300K (slight yellow spectral radiance) to 6000K (very light blue spectral radiance) is ideal for reduced night driving eye strain, depth perception and more accustomed to the human eye needs.
Sunshine w/o clouds at zenith produces a light about 5500K - corrected for light absorption through earths atmosphere. The surface of the sun is 5750K and appears white. Because the surface of the sun emits all wavelengths equally and is "full spectrum", we ideally want a bulb that does the same thing. But this is tricky. Even though there are many bulbs out there that are "full spectrum", some wavelengths in the spectrum are more present than others. Without rambling about physics too much, Kelvin and the visible spectrum are not proportionate but we need a comparison. We don't see in Kelvin, we see in nano-meters of the electromagnetic spectrum.
Using Wien's Displacement Law, we find that a bulb that is color corrected for 6000K will emit visible light to my eyes at 500nm which is an absolute sweet spot in the visible spectrum IMO. The 4300K bulb emits around 660nm which is too predominately red and leaning toward the outer limit of the human eye. Mind you, the 4300K bulb is "full spectrum" and works just fine, but know that this CCT is heavier on the red light emission. Bonus: an HID bulb with a 10,000K CCT emits at about 290nm!
The bulk light emission and peak wavelength is completely useless because the human eye cannot even see it. But the box says full-spectrum HID bulbs, bro! I can drive my Honda Civic just fine!
BTW, I put the 6000K version in today:
https://weisslicht.com/collections/d...22512023666769