6000K is very blue. Not white. 4300K is white. The reason it didn’t look much different than the bulbs you replaced is because your old bulbs had probably shifted color over the years. As an HID bulb ages its color output shifts wavelength from white to blue to purple. So by the time the OEM bulbs finally burn out, they are probably 5500-6000k temp in color.Interestingly, when I went to my local auto parts store to get replacement Xenon HID headlight bulbs, they looked up MY2010 in their system and gave me Osram D3S Xenarc 35W 6000K bulbs.
OEM color temperature is probably closer to 4300K but the 6000K looks pretty good, definitely a little whiter.
With regards to the power rating, the 35W bulbs seem to be functioning fine but should they actually be 55W instead?