I was thinking about getting hid for headlights. But are anything other than 6k whites, i.e. blue or purple good to drive with?

 

you CAN drive with them, a couple of my friends have some 12k ones (purple) but they are fairly worse than my 10k ones >>those are pretty blue. 4300k (yellow) has alot of light output too but only certain cars can pull that off.

 

4300K is not "yellow", it's a warm white. Most factory HIDs are in this range. To get real yellow, you need to go to around 3000K

4300K produces the most light in a white tone that is useable by the human eye. The farther you go up the scale from there, the more the color is for styling and not driving. 6000K is about where to draw the line if actual lighting performance is a concern.

 

If you're going to go HID, go with something that looks good AND is useful. However, if you want to avoid the white to get more color you're going to lose some of the "useful" part. If you want some blue, go for 8000k.