Osram offers both the Cool Blue Intense (~6K) and the Cool Blue Boost (~7K), however the latter supposedly aren't road legal although you can still buy them. But, there's a reason most don't go past that: there's no benefit and at the cost they're asking, most buyers will want the best performing, not the most blue/purple/etc. Also, I wouldn't group Morimoto alongside Philips or Osram, but that's just me.

HID Bulb Change
 

It seems Osram is not following the Kevin chart with them though. There was a test done by retrofitsource.

https://youtu.be/rKEOIUrW39M

Agreed. Back in 2004, I saw an rsx with blue blue hid headlights and at a light, I asked the driver the k temp, to which they responded with 6k. I currently have 8k and, although it does have a blue tint, it’s nowhere near the blue of that rsx.