Can we simply replace our stock 4300k bulbs with some 6k bulbs? or is there some modification needed? Can anyone suggest some good bulbs? I find the stock HID to be more of a yellow/white color and im looking for something with more of a white/blue color

 

Yes, replacing the HID bulbs themselves is all that's needed to get the light color change, but the light output will be reduced when you go with a higher temp bulb like 6000K. The stock 4300K bulbs offer the best light output. If you're not so concerned of your vision at nighttime, go with 6000K bulbs and you will get the blue/white color.